The histopathological features of PG, albeit nonspecific, are helpful in ruling out other causes of ulceration. Microscopy demonstrates a dense dermal and hypodermal infiltrate, mainly composed of neutrophils, and necrosis of the epidermis; a variable number of lymphocytes, macrophages, and sometimes plasma cells are also present. Laboratory tests are performed to evaluate for associated disorders rather than to establish a diagnosis of PG. From a pathogenetic point of view, PG is regarded as a prototype of cutaneous autoinflammatory disease,56 whose physiopathological model has been discussed above for the neutrophilic disorders in general. Immunohistochemical studies have recently contributed to clarify some pathomechanisms of the PG ulcer formation; the latter have shown that the wound bed is the site of neutrophil recruitment; whereas in the wound edge, activated T lymphocytes and macrophages pave the way to ulcer formation.74 Moreover, the chemokine IL-8 is immunohistochemically overexpressed in the wound bed of PG, where there is the predominant neutrophil recruitment and consequent tissue damage, also supported by the intense expression of metalloproteinase (MMP)-9. Finally, the increased expression of IL-17, a proinflammatory cytokine produced primarily by a T helper cell subset termed Th17, suggests its potential role in the PG pathophysiology.74 PG is associated with high morbidity and sometimes mortality because of sepsis or other serious infections.66 Relapses are common and their frequency has been reported in up to 70% of cases.75 Moreover, scarring and disfigurement must be considered. Hallmarks of therapy for PG are the complete suppression of inflammatory disease activity, promotion of wound healing, treatment of secondary infections, treatment of underlying associated diseases, and control of pain.60 In mild cases, dressing changes, prevention of trauma, and supportive care may be sufficient for re-epithelialization to occur. In case of a more widespread disease or rapidly progressive course, systemic treatment is mandatory. Corticosteroids, like prednisolone, 1 to 2 mg per kg per day, are widely used for initial therapy. Cyclosporine A, at a daily dosage of 2 to 5 mg/kg administered intravenously, is an accepted treatment for widespread PG after initial steroids or in combination with steroids.76 Case reports have documented the utility of colchicine, clofazimine, thalidomide, mycophenolate, and immunomodulators such as pimecrolimus and tacrolimus.77 In addition, intravenous immunoglobulins have been shown to be effective.78 In steroid-refractory PG, especially when associated with IBD (particularly CD), TNF-α inhibitors, particularly infliximab, may also have a role as a steroid-sparing agent. PG can respond to the basic treatment of IBD, but its relationship with disease activity is less obvious than in other mucocutaneous EIMs, such as erythema nodosum (EN)79; indeed, about 30% of patients with PG do not experience improvement of their lesions with treatment of the underlying IBD.80
PSV is an uncommon disease of the oral mucosa whose concurrence with IBD has been reported in approximately 70% of cases. Although this entity has been classified among the specific skin lesions of IBD, we suggest that it may simply represent the rare occurrence of oral involvement in patients with PG. PSV is characterized by edematous mucosa covered by numerous friable gray-to-yellow pustules, some being considered true abscesses, producing hemorrhagic ulcerations with vegetating features of the bed (Fig. 5). Any part of the oral cavity may be involved,81,82 but the tongue and floor of the mouth are usually spared.83 Long-standing disease leads to fissuring with a “snail track appearance,” in addition to cobblestoning. Symptoms of burning and pain may be present.84 Other than oral cavity, mucosal membranes at the vaginal, nasal, and rarely periocular areas can also be involved.85 Histopathologically, PSV is characterized by epithelial acanthosis and superficial ulceration with intraepithelial and/or subepithelial microabscesses.83,84 PSV usually parallels the activity of the underlying bowel disease,84 and there are reports of mucosal lesions after regression of IBD flare or after surgical treatment of IBD.
A variety of treatments has been reported. The disease is known to be resistant to local treatment with topical steroids and antibiotic mouthwashes. High-dose systemic steroids may be effective,81 even if recurrence is common after withdrawal of the steroid. Sulfasalazine, dapsone, azathioprine, cyclosporine, and topical tacrolimus represent alternative treatments.86–89 Few cases of PSV have been reported to resolve after complete colectomy.90
Histologically, the most typical features of SS are represented by edema of the dermal papillae and by a dense infiltrate in the dermis, predominantly composed of neutrophils85,93,97 (Fig. 6); also, lymphocytes or histiocytes may be present in the inflammatory infiltrate.93,98 Jordaan,99 in 1989, recognized 3 stages of the SS dermal infiltrate (lymphocytic, neutrophilic, and histiocytic). Moreover, Requena et al100 described a variant of SS, that they named histiocytoid SS. Even though the histopathological diagnostic criteria of SS consistently include the lack of vasculitis, vasculitis changes may be occasionally observed.101 SS, PG, and other neutrophilic dermatosis may occur in the same patient.95
SS can be idiopathic, parainflammatory, paraneoplastic, associated with pregnancy,95 and drug induced.102 The incidence of SS in IBD is much rarer than that of PG; to date, about 40 cases of SS have been reported in association with IBD. SS seems to be predominant in patients with CD rather than in those with UC, the rate of association being about 70% and 30%, respectively.103–106 Patients with colonic disease and women aged between 30 and 50 years have increased risk for developing SS.10,14 Although the syndrome has been described also in some patients with quiescent IBD, the occurrence of the disorder has mainly been reported during relapse of disease. Based on reported data, 28% of the cases will present at the time of diagnosis of IBD, 52% after the diagnosis, and only 20% before the diagnosis.107 IBD and SS are likely to share pathogenetic mechanisms related to the autoinflammation.56 Patients with IBD, particularly UC, may develop a pustular variant of SS, characterized by pustules overlying erythematous papules or red-based pustules.108,109 In patients with IBD-associated SS, arthritis and arthralgias are often seen.107
First-line treatment of SS involves systemic steroids such as prednisone at a starting dose of 0.5 to 1.0 mg/kg and then at tapering doses. Marked symptom improvement may be achieved after a 6-week course of steroids.110 High-potency topical steroids or intralesional glucocorticoids may be used for localized disease. Other first-line options for treatment include colchicine and potassium iodide. Treatments with immunosuppressants like cyclosporine (initial doses of 2–5 mg/kg daily), in monotherapy or in combination with steroids, dapsone (1.5–2 mg/kg daily), azathioprine (1.5–2 mg/kg daily), and cyclophosphamide (1–1.5 mg/kg daily), and TNF-α blockers have been reported to be successful in refractory SS cases.111–113
BADAS is a rare neutrophilic dermatosis characterized by fever and/or flu-like symptoms followed by myalgias, arthralgias, or nondeforming arthritis affecting mainly the small peripheral joints and polymorphic cutaneous manifestations. The disease occurs most commonly from days to years after bowel bypass surgery, but possible associations with IBD have been reported.114,115 BADAS usually follows a chronic relapsing course, albeit self-healing cases have been reported.114 The cutaneous manifestations are usually described as PG-like, but features mimicking those of several other ND, notably SS, hidradenitis suppurativa, and neutrophilic panniculitis, have been described. Although BADAS has been suggested to result from the deposition of circulating immune complexes containing bacterial antigens related to the bacterial overgrowth in the bowel, its actual etiology remains unknown. However, the substantial clinical overlap with the spectrum of ND strongly suggests a pathophysiology related to neutrophil-mediated inflammation.116 Our recent report of a patient with a cutaneous picture consisting with PASH syndrome following bowel bypass surgery supports this hypothesis.117
Steroids represent the mainstay of treatment. In refractory cases, other immunosuppressive agents, such as azathioprine, cyclosporine, or TNF-α antagonists may be effective in controlling both skin and intestinal symptoms. Systemic and topical antibiotics are ineffective but may be useful for treating superinfection of opened skin lesions.118,119
Oral aphthous ulcers are reactive lesions frequently encountered in patients with IBD. Because nutritional deficiencies in iron, folic acid, and vitamin B12 secondary to active IBD predispose toward aphthous ulcer formation, oral aphthae had classically been considered as multifactorial in origin.120 However, based on their histopathological pattern consisting of a neutrophil-mediated inflammation, the aphthous ulcers associated with IBD may be regarded as a form of neutrophilic dermatosis. Aphthae appear as round or oval painful ulcers, with a yellowish or grayish pseudomembranous base and an erythematous border. They are located on the buccal and labial mucosa, lateral and ventral tongue, soft palate, and oropharynx. Minor and major aphthae can be observed. Minor aphthae are shallow, typically <10 mm in diameter, and they usually heal within 2 weeks without sequelae. Major aphthae are larger and deeper and can last for 4 to 6 weeks and heal with scarring. A less common form of recurrent aphthous stomatitis is characterized by numerous ulcers that can fuse to produce herpetiforme lesions. Aphthous stomatitis or ulcers, typically seen in the buccal mucosa and lips, are more common in CD (10% of patients) than UC.5 However, recurrent aphthous stomatitis affects approximately 4% of patients with UC. The onset is abrupt and usually coincides with recurrence or exacerbation of the underlying UC,14,121 even though other studies failed to find a significant correlation with UC activity.5 A study showed that a majority of patients with multiple aphthous ulcers had underlying IBD.122
Treatment of the IBD may result in remission of the oral aphthous stomatitis. Symptomatic relief with topical corticosteroid and topical anesthetics such as viscous xylocaine and steroid elixir may be beneficial. Systemic steroids are used for severe or refractory cases.14,15,18,123
Aseptic abscess syndrome is an emerging clinicopathological entity within the spectrum of neutrophilic dermatoses, first described by André et al.124 Typical presentation includes fever, loss of weight, abdominal pain, and leukocytosis, together with aseptic lesions histologically characterized by inflammatory infiltrates mainly consisting of neutrophils. Deep abscesses are mainly located in the spleen, but almost all the organs can be affected, both intra-abdominal (lymph nodes, liver, and pancreas) and extra-abdominal (lung and brain). Sometimes, more superficial abscesses can be present (peripheral lymph nodes, muscles, pharynx, and testicles); and in 20% of the patients, skin manifestations including cutaneous abscesses (Fig. 7) and features resembling classic neutrophilic dermatoses, notably PG and SS, can be detected.125 The association with IBD is consolidated, being present in 66% of patients, and it justifies the execution of colonoscopy to rule out an underlying intestinal disorder. More rarely, the condition is associated to relapsing polychondritis, or is idiopathic. The diagnosis is based on the clinical presentation, radiological aspects, pathological and laboratory findings, and the exclusion of alternative diagnoses, especially infectious diseases. Because of its aseptic nature, the disease does not respond to antibiotics but regresses quickly when treated with systemic corticosteroids, albeit it frequently follows a relapsing course. Immunosuppressive treatment is required in almost half of the patients, and anti-TNF-α agents may be used.125 The etiology of the aseptic abscesses syndrome is still unknown, but sharing some features with disorders like IBD or ND suggests the presence of a genetic susceptibility and a close relationship with the autoinflammatory disorders. This hypothesis is supported by the finding of an increased number of CCTG microsatellite repeats in the PSTPIP1 promoter region.126
EN, the most common cutaneous manifestation of IBD, affects about 3% to 10% of patients with UC and 4% to 15% of patients with CD.5,14,20,127 The disease affects primarily women between the ages of 25 and 40 years.128 When EN occurs in association with UC, it is typically associated with exacerbation of the colitis even if the severity of the EN does not necessarily parallel the severity of the underlying bowel disease.80 EN rarely precedes the diagnosis of UC.129 EN in patients with CD is mostly associated with colonic involvement.20
The primary lesions are painful, deep, warm, bluish red, tender nodules, 1 to 5 cm in diameter, and distributed symmetrically over the anterior lower legs (Fig. 8). These skin nodules are palpable, do not exhibit suppuration or ulceration, and they change in color to a yellowish hue resembling a bruise on the skin. Old lesions often coexist with the appearance of new nodules, so that nodules at various stages of their evolution may be observed. The eruption may be accompanied by fever, malaise, synovitis, and arthritis. Even though pretibial surfaces are the commonest localization of EN, the knees, ankles, arms, or trunk can also be involved.18 EN heals spontaneously within 6 weeks, without atrophy or scarring, but recurrence occurs in 20% of cases. The histopathology reveals a septal panniculitis; neutrophils typically predominate in early lesions. Granulomatous features may be found in both early and late lesions; whereas, fibrotic subcutaneous septa with multinucleate giant cells are present in late lesions. However, biopsy is generally not necessary as EN may be diagnosed based on the clinical features. Routine laboratory findings include leukocytosis >10,000 per cubic millimeter, elevated erythrocyte sedimentation rate, and increased C-reactive protein levels.130
EN is believed to be a delayed hypersensitivity reaction and has been associated with a number of heterogeneous conditions other than IBD. The inciting antigen is identified in approximately 40% of cases, whereas the disease is idiopathic in most patients. Identifiable causes include bacterial infections (e.g., streptococcal infections, tuberculosis), fungal infections (e.g., histoplasmosis), drugs (e.g., oral contraceptive pills), malignancy (lymphomas), and pregnancy.131 Sarcoidosis and Behçet disease are other associated conditions. In a recent Spanish study on 106 patients with EN, sarcoidosis, accounting for 22% of cases, was the most frequent systemic disease causing EN.132 The prevalent underlying cause varies by the population and the geographic location. In children, streptococcal infections seem to be the most common cause. Given the broad variety of possible triggers for EN, a thorough history and physical examination are essential for narrowing the list of possible etiologies. A reasonable laboratory and radiologic workup might include antistreptolysin O or anti-DNase-B levels, a chest x-ray, stool cultures, a tuberculin skin test, and a urine pregnancy test.
When EN is associated with IBD, because skin lesions mirror bowel disease activity and flare up, treatments targeting underlying IBD usually lead to the remission of the cutaneous manifestations.133 Supportive therapy, including bed rest and avoidance of contact irritation of affected areas, has a relevant role. However, in situations where lesions occur during the quiescent phase, low doses of oral steroids can lead to rapid remission of the cutaneous lesions in most cases.20 Other effective alternatives include immunomodulating agents such as colchicine, dapsone, and thalidomide and immunosuppressants such as cyclosporine, azathioprine, and methotrexate. In resistant or highly relapsing cases, TNF-α antagonists have been used with successful results.134
There is no relationship between the course of psoriasis and the activity of IBD. In patients with both CD and psoriasis, the onset of psoriasis usually precedes that of CD.144,145 Topical corticosteroids, salicylic acid, and vitamin D analogs are used in mild disease. In severe cases, systemic retinoids, methotrexate, cyclosporine, and TNF-α antagonists have to be considered.
Both cutaneous small-vessel vasculitis and cutaneous polyarteritis nodosa (C-PAN) are uncommon skin manifestations of IBD. Cutaneous small-vessel vasculitis is the most common type of cutaneous vasculitis and affects mainly the skin postcapillary venules.146 The cutaneous picture is typically polymorphous147 and ranges from palpable purpura to urticarial and necrotic ulcerative lesions predominantly involving the legs (Fig. 10), whereas its extracutaneous, particularly renal, manifestations are relatively uncommon. The skin lesions of cutaneous small-vessel vasculitis arise as a simultaneous crop and usually resolve within several weeks or a few months; approximately 10% of patients follow a chronic relapsing course more than a period ranging from few to several years. The histopathological pattern is the so-called leukocytoclastic vasculitis, characterized by dermal perivascular infiltrates mainly composed of neutrophils with karyorrhexis of nuclei and fibrinoid necrosis of vessel walls148 (Fig. 10). The therapeutic approach in patients with mild disease consists of only topical corticosteroids, whereas, systemic corticosteroids, namely methylprednisolone at the initial dose of 0.8 to 1 mg/kg daily, are the first-line agents for patients with painful ulcerative necrotic skin lesions. A number of steroid-sparing immunosuppressants, notably cyclosporine (2–5 mg/kg daily), may be associated to corticosteroid in highly relapsing cases or used in monotherapy in patients in whom corticosteroids are contraindicated.146 Polyarteritis nodosa is a rare, severe necrotizing vasculitis of small- and medium-sized arteries149 affecting multiple organ systems; C-PAN is a variant of polyarteritis nodosa confined to the skin, although controversy exists on whether or not it simply represents an early or less aggressive form of polyarteritis nodosa.146,150 C-PAN presents as a single or multiple tender nodules commonly located on the distal lower extremities. Early in the course of C-PAN, lesions show the typical pattern of leukocytoclastic vasculitis, whereas later in the disease process, the infiltrate is predominantly composed of lymphocytes and histiocytes151; granulomatous features reminiscent of those of classic CD may be seen when there is coexistence with IBD.152 Up to 10% of C-PAN cases are associated with IBD.153 Treatment of C-PAN consists of systemic corticosteroids, namely methylprednisolone at the initial dose of 0.8 to 1 mg/kg daily, which usually controls the disease. Low-dose methotrexate (7.5–20 mg/wk) may be considered for cases unresponsive to corticosteroids.146
Epidermolysis bullosa acquisita (EBA) is an autoimmune disease manifesting as subepidermal blistering and scarring, mainly localized in anatomical areas prone to trauma, such as the hands, knees (Fig. 11), and feet; mucosae may also be involved. EBA is characterized by autoantibodies of the IgG-isotype specific to type VII collagen, the main constituent of anchoring fibrils at the dermal–epidermal junction.154 Binding of autoantibodies to type VII collagen triggers an inflammatory reaction, including fixation of complement and Fc-dependent activation of leucocytes.155 Activated granulocytes release reactive oxygen intermediates and proteases leading to epithelial injury and blister formation.156,157 Clinically, EBA may manifest as tense vesicles and bullae, evolving into erosions. The blisters may be hemorrhagic and usually heal with scar and milia formation. Inflammatory features, including erythema, urticarial plaques, and pruritus may occur. EBA diagnosis needs to be confirmed by immunopathological studies including direct immunofluorescence on perilesional skin and indirect immunofluorescence on sodium split skin. Direct immunofluorescence reveals deposits of IgG (rarely IgA) and or C3 at the dermal–epidermal junction (Fig. 11C), whereas indirect immunofluorescence shows IgG (rarely IgA) and or C3 at the floor of the split skin (Fig. 11D). Recently, an immunoenzymatic method has been set up to detect circulating autoantibodies against type VII collagen.154 Systemic diseases are often associated with EBA, including CD and, less frequently, UC.158 A study found that the prevalence of IBD in patients with EBA was about 25%.159 The pathogenetic mechanism underlying the association between EBA and IBD may be related to the epitope-spreading phenomenon. In fact, type VII collagen is also expressed in the basement membrane of intestinal epithelium. It may be hypothesized that chronic inflammation in the intestine predisposes patients with IBD to develop autoantibodies against type VII collagen, which in turn attack the skin at the dermal–epidermal junction resulting in the typical blistering lesions of EBA.160 The onset of the gastrointestinal symptoms generally precedes or occurs simultaneously with the autoimmune skin disease.160,161 Less frequently, the diagnosis of IBD follows the development of the blistering disorder.160,162 The treatment of EBA is represented by immunosuppressants and anti-inflammatory agents, including systemic corticosteroids, dapsone,163 colchicine,164 cyclosporine,165 mycophenolate mofetil,166 azathioprine, and recently, the anti-CD20 mAb rituximab.167
Among the EIMs of IBD, the skin is one of the most frequently involved organ systems. In addition to mucocutaneous manifestations affecting sites that are in continuity with the bowel, namely perianal, peristomal, and orofacial regions, showing the same granulomatous histology seen in IBD, there are both skin diseases associated with IBD and reactive cutaneous manifestations. Whereas, the former, albeit linked to IBD, are distinctive entities, such as EN and psoriasis, the latter are regarded as a skin expression of IBD because of sharing physiopathological pathways. Among this setting, there are PG and SS, 2 classic neutrophilic dermatoses that have recently been classified among autoinflammatory diseases. Autoinflammatory diseases are clinically characterized by recurrent episodes of sterile inflammation in the affected organs, without high titers of circulating autoantibodies and autoreactive T cells. All the above conditions may precede, occur simultaneously, or follow the onset of the intestinal disease. The immunosuppressive treatment for the underlying IBD usually, albeit not always, achieves the control of the mucocutaneous manifestations. So, all patients with IBD should be closely examined for skin manifestations by gastroenterologists. However, it is mandatory for dermatologists to be alert in any patient presenting with any neutrophilic dermatosis for the possibility of an underlying IBD. Finally, the protean cutaneous adverse reactions caused by immunosuppressants, particularly TNF-α inhibitors, used for the management of IBD, mainly include psoriasis-like, eczema-like, and lichenoid eruptions, drug-induced cutaneous lupus erythematosus, and nonmelanoma skin cancer. Cutaneous manifestations should be promptly recognized and correctly diagnosed by gastroenterologists and dermatologists together to quickly establish an adequate treatment.
1. Huang BL, Chandra S, Shih DQ. Skin manifestations of inflammatory bowel disease. Front Physiol. 2012;3:1–13.
2. Veloso FT. Extraintestinal manifestations of inflammatory bowel disease: do they influence treatment and outcome? World J Gastroenterol. 2011;17:2702–2707.
3. Bernstein CN, Blanchard JF, Rawsthorne P, et al.. The prevalence of extraintestinal diseases in inflammatory bowel disease: a population-based study. Am J Gastroenterol. 2001;96:1116–1122.
4. Vind I, Riis L, Jess T, et al.; DCCD study group. Increasing incidences of inflammatory bowel disease and decreasing surgery rates in Copenhagen City and County, 2003-2005: a population-based study from the Danish Crohn colitis database. Am J Gastroenterol. 2006;101:1274–1282.
5. Vavricka SR, Brun L, Ballabeni P, et al.. Frequency and risk factors for extraintestinal manifestations in the Swiss inflammatory bowel disease cohort. Am J Gastroenterol. 2011;106:110–119.
6. Veloso FT, Ferreira JT, Barros L, et al.. Clinical outcome of Crohn's disease: analysis according to the vienna classification and clinical activity. Inflamm Bowel Dis. 2001;7:306–313.
7. Veloso FT, Carvalho J, Magro F. Immune-related systemic manifestations of inflammatory bowel disease. A prospective study of 792 patients. J Clin Gastroenterol. 1996;23:29–34.
8. Stadnicki A, Colman RW. Extraintestinal manifestations of inflammatory bowel disease: new insights into pathogenesis and clinical setting. Gastroenterol Pol. 1998;5:517–523.
9. Williams H, Walker D, Orchard TR. Extraintestinal manifestations of inflammatory bowel disease. Curr Gastroenterol Rep. 2008;10:597–605.
10. Ardizzone S, Puttini PS, Cassinotti A, et al.. Extraintestinal manifestations of inflammatory bowel disease. Dig Liver Dis. 2008;40(suppl 2):S253–S259.
11. Danese S, Semeraro S, Papa A, et al.. Extraintestinal manifestations in inflammatory bowel disease. World J Gastroenterol. 2005;11:7227–7236.
12. Burgdorf W. Cutaneous manifestations of Crohn's disease. J Am Acad Dermatol. 1981;5:689–695.
13. Palamaras I, El-Jabbour J, Pietropaolo N, et al.. Metastatic Crohn's disease: a review. J Eur Acad Dermatol Venereol. 2008;22:1033–1043.
14. Timani S, Mutasim DF. Skin manifestations of inflammatory bowel disease. Clin Dermatol. 2008;26:265–273.
15. Trost LB, McDonnell JK. Important cutaneous manifestations of inflammatory bowel disease. Postgrad Med J. 2005;81:580–585.
16. Passarini B, Infusino SD, Barbieri E, et al.. Cutaneous manifestations in inflammatory bowel diseases: eight cases of psoriasis induced by anti-tumor-necrosis-factor antibody therapy. Dermatology. 2007;215:295–300.
17. Mnif L, Amouri A, Tahri N, Cutaneous manifestations of inflammatory bowel disease. Tunis Med. 2010;88:420–423.
18. Levine JS, Burakoff R. Extraintestinal manifestations of inflammatory bowel disease. Gastroenterol Hepatol (N Y). 2011;7:235–2411.
19. Torres J, Buche S, Delaporte E, et al.. Skin side effects of inflammatory bowel disease therapy. Inflamm Bowel Dis. 2013;19:1086–1098.
20. Georgiou G, Pasmatzi E, Monastirli A, et al.. Cutaneous manifestations of inflammatory bowel disease. Hosp Chron. 2006;1:158–168.
21. Xavier RJ, Podolsky DK. Unravelling the pathogenesis of inflammatory bowel disease. Nature. 2007;448:427–434.
22. Sangwan YP, Schoetz DJ Jr, Murray JJ, et al.. Perianal Crohn's disease. Results of local surgical treatment. Dis Colon Rectum. 1996;39:529–535.
23. Lockhart-Mummery HE. Symposium. Crohn's disease: anal lesions. Dis Colon Rectum. 1975;18:200–202.
24. McClane SJ, Rombeau JL. Anorectal Crohn's disease. Surg Clin North Am. 2001;81:169–183.
25. Williams DR, Coller JA, Corman ML, et al.. Anal complications in Crohn's disease. Dis Colon Rectum. 1981;24:22–24.
26. Keighley MR, Allan RN. Current status and influence of operation on perianal Crohn's disease. Int J Colorectal Dis. 1986;1:104–107.
27. Vermeire S, Van Assche G, Rutgeerts P. Perianal Crohn's disease: classification and clinical evaluation. Dig Liver Dis. 2007;39:959–962.
28. Khaikin M, Chowers Y, Zmora O. Perianal Crohn's disease. Isr Med Assoc J. 2007;9:163–168.
29. Rutgeerts P. Review article: treatment of perianal fistulizing Crohn's disease. Aliment Pharmacol Ther. 2004;20(suppl 4):106–110.
30. Bouguen G, Siproudhis L, Bretagne JF, et al.. Nonfistulizing perianal Crohn's disease: clinical features, epidemiology, and treatment. Inflamm Bowel Dis. 2010;16:1431–1442.
31. Wolff BG, Culp CE, Beart RW Jr, et al.. Anorectal Crohn's disease. A long-term perspective. Dis Colon Rectum. 1985;28:709–711.
32. Satsangi J, Silverberg MS, Vermeire S, et al.. The Montreal classification of inflammatory bowel disease: controversies, consensus, and implications. Gut. 2006;55:749–753.
33. Williams JG, Rothenberger DA, Nemer FD, et al.. Fistula-in-ano
in Crohn's disease. Results of aggressive surgical treatment. Dis Colon Rectum. 1991;34:378–384.
34. Singh B, McC Mortensen NJ, Jewell DP, et al.. Perianal Crohn's disease. Br J Surg. 2004;91:801–814.
35. Platell C, Mackay J, Collopy B, et al.. Anal pathology in patients with Crohn's disease. Aust N Z J Surg. 1996;66:5–9.
36. Siproudhis L, Mortaji A, Mary JY, et al.. Anal lesions: any significant prognosis in Crohn's disease? Eur J Gastroenterol Hepatol. 1997;9:239–243.
37. Bouchard D, Denis J. Anoperineal Crohn's disease. Acta Endoscop. 1999;29:283–301.
38. Fleshner PR, Schoetz DJ Jr, Roberts PL, et al.. Anal fissure in Crohn's disease: a plea for aggressive management. Dis Colon Rectum. 1995;38:1137–1143.
39. Bonheur JL, Braunstein J, Korelitz BI, et al.. Anal skin tags in inflammatory bowel disease: new observations and a clinical review. Inflamm Bowel Dis. 2008;14:1236–1239.
40. Malins TJ, Wilson A, Ward-Booth RP. Recurrent buccal space abscesses: a complication of Crohn's disease. Oral Surg Oral Med Oral Pathol. 1991;72:19–21.
41. Plauth M, Jenss H, Meyle J. Oral manifestations of Crohn's disease. An analysis of 79 cases. J Clin Gastroenterol. 1991;13:29–37.
42. Quezada S, Turner PL, Alexiev B, et al.. Severe refractory orofacial Crohn's disease: report of a case. Dig Dis Sci. 2009;54:2290–2295.
43. Staines KS, Green R, Felix DH. The management of fistulizing oral Crohn's disease with infliximab. J Oral Pathol Med. 2007;36:444–446.
44. Sheldon DG, Sawchuck L, Kozarek K, et al.. Twenty cases of peristomal pyoderma gangrenosum. Diagnostic implications and clinical management. Arch Surg. 2000;135:564–569.
45. Lebwohl M, Fleischmajer R, Janowitz H, et al.. Metastatic Crohn's disease. J Am Acad Dermatol. 1984;10:33–38.
46. Hawryluk EB, Izikson L, English JC. Non-infectious granulomatous diseases of the skin and their associated systemic diseases: an evidence-based update to important clinical questions. Am J Clin Dermatol. 2010;11:171–181.
47. Guest GD, Fink RL. Metastatic Crohn's disease: a case report of an unusual variant and review of the literature. Dis Colon Rectum. 2000;43:1764–1766.
48. Kafity AA, Pellegrini AE, Fronkes JJ. Metastatic Crohn's disease. A rare cutaneous manifestation. J Clin Gastroenterol. 1993;17:300–303.
49. Hoffmann RM, Kruis W. Rare extraintestinal manifestations of inflammatory bowel disease. Inflamm Bowel Dis. 2004;10:140–147.
50. Konrad A, Seibold F. Response of cutaneous Crohn's disease to infliximab and methotrexate. Dig Liver Dis. 2003;35:351–356.
51. Kugathasan S, Miranda A, Nocton J, et al., Binion DG Dermatologic manifestations of Crohn disease in children: response to infliximab. J Pediatr Gastroenterol Nutr. 2003;37:150–154.
52. Nesterovitch AB, Gyorfy Z, Hoffman MD, et al.. Alteration in the gene encoding protein tyrosine phosphatase nonreceptor type 6 (PTPN6/SHP1) may contribute to neutrophilic dermatoses. Am J Pathol. 2011;178:1434–1441.
53. McDermott MF, Aksentijevich I, Galon J, et al.. Germline mutations in the extracellular domains of the 55 kDa TNF receptor, TNFR1, define a family of dominantly inherited autoinflammatory syndromes. Cell. 1999;97:133–144.
54. Kastner DL, Aksentijevich I, Goldbach-Mansky R. Autoinflammatory disease reloaded: a clinical perspective. Cell. 2010;140:784–790.
55. Doria A, Zen M, Bettio S, et al.. Autoinflammation and autoimmunity: bridging the divide. Autoimmun Rev. 2012;12:22–30.
56. Marzano AV, Ishak RS, Saibeni S, et al.. Autoinflammatory skin disorders in inflammatory bowel diseases, pyoderma gangrenosum and Sweet's syndrome: a comprehensive review and disease classification criteria. Clin Rev Allergy Immunol. 2013 [epub ahead of print].
57. Wollina U, Haroske G. Pyoderma gangraenosum. Curr Opin Rheumatol. 2011;23:50–56.
58. Levitt MD, Ritchie JK, Lennard-Jones JE, et al.. Pyoderma gangrenosum in inflammatory bowel disease. Br J Surg. 1991;78:676–678.
59. Galbraith SS, Drolet BA, Kugathasan S, et al.. Asymptomatic inflammatory bowel disease presenting with mucocutaneous findings. Pediatrics. 2005;116:e439–e444.
60. Hasselmann DO, Bens G, Tilgen W, et al.. Pyoderma gangrenosum: clinical presentation and outcome in 18 cases and review of the literature. J Dtsch Dermatol Ges. 2007;5:560–564.
61. Nguyen KH, Miller JJ, Helm KF. Case reports and a review of the literature on ulcers mimicking pyoderma gangrenosum. Int J Dermatol. 2003;42:84–94.
62. Callen JP. Pyoderma gangrenosum. Lancet. 1996;351:581–585.
63. Ahronowitz I, Harp J, Shinkai K. Etiology and management of pyoderma gangrenosum: a comprehensive review. Am J Clin Dermatol. 2012;13:191–211.
64. Ruocco E, Sangiuliano S, Gravina AG, et al.. Pyoderma gangrenosum: an updated review. J Eur Acad Dermatol Venereol. 2009;23:1008–1017.
65. Marzano AV, Tourlaki A, Alessi E, et al.. Widespread idiopathic pyoderma gangrenosum evolved from ulcerative to vegetative type: a 10-year history with a recent response to infliximab. Clin Exp Dermatol. 2008;33:156–159.
66. Marzano AV, Trevisan V, Galloni C, et al.. Fatal bullous pyoderma gangrenosum in a patient with Klinefelter's syndrome. Acta Derm Venereol. 2008;88:158–159.
67. Marzano AV, Ishak RS, Lazzari R, et al.. Vulvar pyoderma gangrenosum with renal involvement. Eur J Dermatol. 2012;22:537–539.
68. Wallach D, Vignon-Pennamen MD. From acute febrile neutrophilic dermatosis to neutrophilic disease: forty years of clinical research. J Am Acad Dermatol. 2006;55:1066–1071.
69. Fox LP, Geyer AS, Husain S, et al.. Bullous pyoderma gangrenosum as the presenting sign of fatal acute myelogenous leukemia. Leuk Lymphoma. 2006;47:147–150.
70. Torok L, Kirschner A, Gurzo M, et al.. Bullous pyoderma gangrenosum as a manifestation of leukemia cutis. Eur J Dermatol. 2000;10:463–465.
71. Gungor K, Gonen S, Kisakol G, et al.. ANCA positive propylthiouracil induced pyoderma gangrenosum. J Endocrinol Invest. 2006;29:575–576.
72. White LE, Villa MT, Petronic-Rosic V, et al.. Pyoderma gangrenosum related to a new granulocyte colony-stimulating factor. Skinmed. 2006;5:96–98.
73. Sagara R, Kitami A, Nakada T, et al.. Adverse reactions to gefitinib (Iressa): revealing sycosis- and pyoderma gangrenosum-like lesions. Int J Dermatol. 2006;45:1002–1003.
74. Marzano AV, Cugno M, Trevisan V, et al.. Role of inflammatory cells, cytokines and matrix metalloproteinases in neutrophil-mediated skin diseases. Clin Exp Immunol. 2010;162:100–107.
75. Vidal D, Puig L, Gilaberte M, et al.. Review of 26 cases of classical pyoderma gangrenosum: clinical and therapeutic features. J Dermatol Treat. 2004;15:146–152.
76. Marzano AV, Trevisan V, Lazzari R, et al.. Pyoderma gangrenosum: study of 21 patients and proposal of a “clinicotherapeutic” classification. J Dermatolog Treat. 2011;22:254–260.
77. Marzano AV, Trevisan V, Lazzari R, et al.. Topical tacrolimus for the treatment of localized, idiopathic, newly diagnosed pyoderma gangrenosum. J Dermatolog Treat. 2010;21:140–143.
78. Gupta AK, Shear NH, Sauder DN. Efficacy of human intravenous immune globulin in pyoderma gangrenosum. J Am Acad Dermatol. 1995;32:140–142.
79. Carrasco Cubero C, Ruiz Tudela MM, Salaberri Maestrojuan JJ, et al.. Pyoderma gangrenosum associated with inflammatory bowel disease. Report of two cases with good response to infliximab. Reumatol Clin. 2012;8:90–92.
80. Mir-Madjlessi SH, Taylor JS, Farmer RG. Clinical course and evolution of erythema nodosum and pyoderma gangrenosum in chronic ulcerative colitis: a study of 42 patients. Am J Gastroenterol. 1985;80:615–620.
81. Hegarty AM, Barrett AW, Scully C. Pyostomatitis vegetans. Clin Exp Dermatol. 2004;29:1–7.
82. Nigen S, Poulin Y, Rochette L, et al.. Pyodermatitis-pyostomatitis vegetans: two cases and a review of the literature. J Cutan Med Surg. 2003;7:250–255.
83. Femiano F, Buonaiuto C, Gombos F, et al.. Pilot study on recurrent aphthous stomatitis (RAS): a randomized placebo-controlled trial for the comparative therapeutic effects of systemic prednisone and systemic montelukast in subjects unresponsive to topical therapy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010;109:402–407.
84. Ficarra G, Baroni G, Massi D. Pyostomatitis vegetans: cellular immune profile and expression of IL-6, IL-8 and TNF-alpha. Head Neck Pathol. 2010;4:1–9.
85. Fitzgerald RL, McBurney EI, Nesbitt LT Jr. Sweet's syndrome. Int J Dermatol. 1996;35:9–15.
86. Ruiz-Roca JA, Berini-Aytes L, Gay-Escoda C. Pyostomatitis vegetans. Report of two cases and review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005;99:447–454.
87. Werchniak AE, Storm CA, Plunkett RW, et al.. Treatment of pyostomatitis vegetans with topical tacrolimus. J Am Acad Dermatol. 2005;52:722–723.
88. Brinkmeier T, Frosch PJ. Pyodermatitis-pyostomatitis vegetans: a clinical course of two decades with response to cyclosporine and lowdose prednisolone. Acta Derm Venereol. 2001;81:134–136.
89. Leibovitch I, Ooi C, Huilgol SC, et al.. Pyodermatitis-pyostomatitis vegetans of the eyelids case report and review of the literature. Ophthalmology. 2005;112:1809–1813.
90. Ozdil S, Akyüz F, Pinarbasi B, et al.. Okten AUlcerative colitis: analyses of 116 cases (do extraintestinal manifestations effect the time to catch remission?). Hepatogastroenterology. 2004;51:768–770.
91. Sweet RD. An acute febrile neutrophilic dermatosis. Br J Dermatol. 1964;76:349–356.
92. Cohen PR, Kurzrock R. Sweet's syndrome revisited: a review of disease concepts. Int J Dermatol. 2003;42:761–778.
93. Wallach D. Neutrophilic dermatoses: an overview. Clin Dermatol. 2000;18:229–231.
94. Caughman W, Stern R, Haynes H. Neutrophilic dermatosis of myeloproliferative disorders. J Am Acad Dermatol. 1983;9:751–758.
95. von den Driesch P. Sweet's syndrome (acute febrile neutrophilic dermatosis). J Am Acad Dermatol. 1994;31:535–556.
96. Cohen PR. Sweet's syndrome: a comprehensive review of an acute febrile neutrophilic dermatosis. Orphanet J Rare Dis. 2007;2:34.
97. Cohen PR, Kurzrock R. Sweet's syndrome: a neutrophilic dermatosis classically associated with acute onset and fever. Clin Dermatol. 2000;18:265–282.
98. Corazza M, Lauriola MM, Borghi A, et al.. Sweet's syndrome: a retrospective clinical, histopathological and immunohistochemical analysis of 11 cases. Acta Derm Venereol. 2008;88:601–606.
99. Jordaan HF. Acute febrile neutrophilic dermatosis: a histopathological study of 37 patients and a review of the literature. Am J Dermatopathol. 1989;11:99–111.
100. Requena L, Kutzner H, Palmedo G, et al.. Histiocytoid Sweet syndrome—a dermal infiltration of immature neutrophilic granulocytes. Arch Dermatol. 2005;141:834–842.
101. Ratzinger G, Burgdorf W, Zelger BG, et al.. Acute febrile neutrophilic dermatosis: a histopathologic study of 31 cases with review of literature. Am J Dermatopathol. 2007;29:125–133.
102. Prevost-Blank PL, Shwayder TD. Sweet's syndrome secondary to granulocyte colony stimulating factor. J Am Acad Dermatol. 1996;35:995–997.
103. Burrows NP. Sweet's syndrome in association with Crohn's disease. Clin Exp Dermatol. 1995;20:279–280.
104. Actis GC, Lagget M, Cinacio A, et al.. Recurrent Sweet's syndrome in reactivated Crohn's disease. J Clin Gastroenterol. 1995;21:317–319.
105. Calvo Catala J, Gonzalez Perez JA, Febrer Bosch I, et al.. Sweet's syndrome. Its association with chronic inflammatory bowel disease. Ann Med Intern. 1990;7:364–366.
106. Paoluzi OA, Crispino P, Amantea A, et al.. Diffuse febrile dermatosis in a patient with active ulcerative colitis under treatment with steroids and azathioprine: a case of Sweet's syndrome. Case report and review of literature. Dig Liver Dis. 2004;36:361–366.
107. Travis S, Innes N, Davies MG, et al.. Sweet's syndrome: an unusual cutaneous feature of Crohn's disease or ulcerative colitis. The South West Gastroenterology Group. Eur J Gastroenterol Hepatol. 1997;9:715–720.
108. Sommer S, Wilkinson SM, Merchant WJ, et al.. Sweet's syndrome presenting as palmoplantar pustulosis. J Am Acad Dermatol. 2000;42:332–334.
109. Sarkany RP, Burrows NP, Grant JW, et al.. The pustular eruption of ulcerative colitis: a variant of Sweet's syndrome? Br J Dermatol. 1998;138:365–366.
110. Cohen PR, Talpaz M, Kurzrock R. Malignancy-associated Sweet's syndrome: review of the world literature. J Clin Oncol. 1988;6:1887–1897.
111. Ali M, Duerksen DR. Ulcerative colitis and Sweet's syndrome: a case report and review of the literature. Can J Gastroenterol. 2008;22:296–298.
112. Cohen PR. Neutrophilic dermatoses: a review of current treatment options. Am J Clin Dermatol. 2009;10:301–312.
113. Larsen S, Bendtzen K, Nielsen OH. Extraintestinal manifestations of inflammatory bowel disease: epidemiology, diagnosis, and management. Ann Med. 2010;42:97–114.
114. Patton T, Jukic D, Juhas E. Atypical histopathology in bowel-associated dermatosis–arthritis syndrome: a case report. Dermatol Online J. 2009;15:3.
115. Cox NH, Palmer JG. Bowel-associated dermatitis-arthritis syndrome associated with ileo-anal pouch anastomosis, and treatment with mycophenolate mofetil. Br J Dermatol. 2003;149:1296–1297.
116. Marzano AV, Menicanti C, Crosti C, et al.. Neutrophilic dermatoses and inflammatory bowel diseases. G Ital Dermatol Venereol. 2013;148:185–196.
117. Marzano AV, Ishak RS, Colombo A, et al.. Pyoderma gangrenosum, acne and suppurative hidradenitis syndrome following bowel bypass surgery. Dermatology. 2012;225:215–219.
118. Dicken CH. Bowel-associated dermatosis-arthritis syndrome: bowel bypass syndrome without bowel bypass. J Am Acad Dermatol. 1986;14:792–796.
119. Truchuelo MT, Alcántara J, Vano-Galván S, et al.. Bowel-associated dermatosis-arthritis syndrome: another cutaneous manifestation of inflammatory intestinal disease. Int J Dermatol. 2012 [epub ahead of print].
120. Woo SB, Sonis ST. Recurrent aphthous ulcers: a review of diagnosis and treatment. J Am Dent Assoc. 1996;127:1202–1213.
121. Beitman RG, Frost SS, Roth JL. Oral manifestations of gastrointestinal disease. Dig Dis Sci. 1981;26:741–747.
122. Letsinger JA, McCarty MA, Jorizzo JL. Complex aphthosis: a large case series with evaluation algorithm and therapeutic ladder from topicals to thalidomide. J Am Acad Dermatol. 2005;52:500–508.
123. Basu MK, Asquith P. Oral manifestations of inflammatory bowel disease. Clin Gastroenterol. 1980;9:307–321.
124. André M, Aumaitre O, Marcheix JC, et al.. Aseptic systemic abscesses preceding diagnosis of Crohn's disease by three years. Dig Dis Sci. 1995;40:525–527.
125. André M, Aumaître O. Aseptic abscesses syndrome. Rev Med Interne. 2011;32:678–688.
126. André M, Aumaître O, Grateau G, et al.. Longest form of CCTG microsatellite repeat in the promoter of the CD2BP1/PSTPIP1 gene is associated with aseptic abscesses and with Crohn disease in French patients. Dig Dis Sci. 2010;55:1681–1688.
127. Lebwohl M, Lebwohl O. Cutaneous manifestations of inflammatory bowel disease. Inflamm Bowel Dis. 1998;4:142–148.
128. Turkcapar N, Toruner M, Soykan I, et al.. The prevalence of extraintestinal manifestations and HLA association in patients with inflammatory bowel disease. Rheumatol Int. 2006;26:663–668.
129. Weinstein M, Turner D, Avitzur Y. Erythema nodosum as a presentation of inflammatory bowel disease. CMAJ. 2005;173:145–146.
130. Mert A, Ozaras R, Tabak F, et al.. Erythema nodosum: an experience of 10 years. Scand J Infect Dis. 2004;36:424–427.
131. Cahill J, Sinclair R. Cutaneous manifestations of systemic disease. Aust Fam Physician. 2005;34:335–340.
132. García-Porrúa C, González-Gay MA, Vázquez-Caruncho M, et al.. Erythema nodosum. Etiologic and predictive factors in a defined population. Arthritis Rheum. 2000;43:584–592.
133. Orchard T. Extraintestinal complications of inflammatory bowel disease. Curr Gastroenterol Rep. 2003;5:512–517.
134. Kaufman I, Caspi D, Yeshurun D, et al.. The effect of infliximab on extraintestinal manifestations of Crohn's disease. Rheumatol Int. 2005;25:406–410.
135. Najarian DJ, Gottlieb AB. Connections between psoriasis and Crohn's disease. J Am Acad Dermatol. 2003;48:805–821.
136. Wu JJ, Nguyen TU, Poon KY, et al.. The association of psoriasis with autoimmune diseases. J Am Acad Dermatol. 2012;67:924–930.
137. Lee F, Bellary S, Francis C. Increased occurrence of psoriasis in patients with Crohn's disease and their relatives. Am J Gastroenterol. 1990;85:962–963.
138. Yates VM, Watkinson G, Kelman A. Further evidence for an association between psoriasis, Crohn's disease and ulcerative colitis. Br J Dermatol. 1982;106:323–330.
139. Cho JH, Brant SR. Recent insights into the genetics of inflammatory bowel disease. Gastroenterology. 2011;140:1704–1712.
140. Binus AM, Han J, Qamar AA, et al.. Associated comorbidities in psoriasis and inflammatory bowel disease. J Eur Acad Dermatol Venereol. 2012;26:644–650.
141. Tesmer LA, Lundy SK, Sarkar S, et al.. Th17 cells in human disease. Immunol Rev. 2008:223:87–113.
142. Asarch A, Barak O, Loo DS, et al.. Th17 cells: a new therapeutic target in inflammatory dermatoses. J Dermatolog Treat. 2008:19:318–326.
143. Di Cesare A, DiMeglio P, Nestle FO. The IL-23/Th17 axis in the immunopathogenesis of psoriasis. J Invest Dermatol. 2009;129:1339–1350.
144. Hoffmann R, Schieferstein G, Schunter F, et al.. Increased occurrence of psoriasis in patients with Crohn's disease and their relatives. Am J Gastroenterol. 1991;86:787–788.
145. Hughes S, Williams S, Turnberg L. Crohn's disease and psoriasis. N Engl J Med. 1983;308:101.
146. Marzano AV, Vezzoli P, Berti E. Skin involvement in cutaneous and systemic vasculitis. Autoimmun Rev. 2013;12:467–476.
147. Tsiamoulos Z, Karamanolis G, Polymeros D, et al.. Leukocytoclastic vasculitis as an onset symptom of Crohn's disease. Case Rep Gastroenterol. 2008;2:410–414.
148. Akbulut S, Ozaslan E, Topal F, et al.. Ulcerative colitis presenting as leukocytoclastic vasculitis of skin. World J Gastroenterol. 2008;14:2448–2450.
149. Siberry GK, Cohen BA, Johnson B. Cutaneous polyarteritis nodosa. Arch Dermatol. 1994;130:884–889.
150. Decleva I, Marzano AV, Barbareschi M, et al.. Cutaneous manifestations in systemic vasculitis. Clin Rev Allergy Immunol. 1997;15:5–20.
151. Morgan AJ, Schwartz RA. Cutaneous polyarteritis nodosa: a comprehensive review. Int J Derm. 2010;49:750–756.
152. Solley GO, Winkelmann RK, Rovelstad RA. Correlation between regional enteritis and cutaneous polyarteritis nodosa: two cases and review of the literature. Gastroenterology. 1975;69:235–239.
153. Daoud MS, Jutton KP, Gibson LE. Cutaneous periarteritis nodosa: a clinicopathological study of 79 cases. Br J Dermatol. 1997;136:706–713.
154. Marzano AV, Cozzani E, Fanoni D, et al.. Diagnosis and disease severity assessment of epidermolysis bullosa acquisita by ELISA for anti-type VII collagen autoantibodies: an Italian multicentre study. Br J Dermatol. 2013;168:80–84.
155. Mihai S, Chiriac MT, Takahashi K, et al.. The alternative pathway of complement activation is critical for blister induction in experimental epidermolysis bullosa acquisita. J Immunol. 2007;178:6514–6521.
156. Chiriac MT, Roesler J, Sindrilaru A, et al.. NADPH oxidase is required for neutrophil-dependent autoantibody-induced tissue damage. J Pathol. 2007;212:56–65.
157. Shimanovich I, Mihai S, Oostingh GJ, et al.. Granulocyte-derived elastase and gelatinase B are required for dermal–epidermal separation induced by autoantibodies from patients with epidermolysis bullosa acquisita and bullous pemphigoid. J Pathol. 2004;204:519–527.
158. Chen M, O'Toole EA, Sanghavi J, et al.. The epidermolysis bullosa acquisita antigen (type VII collagen) is present in human colon and patients with crohn's disease have autoantibodies to type VII collagen. J Invest Dermatol. 2002;118:1059–1064.
159. Van't Veen AJ, Heule F, Vuzevski VD, et al.. Epidermolysis bullosa acquisita. Br J Dermatol. 1994;131:724–725.
160. Hundorfean G, Neurath MF, Sitaru C. Autoimmunity against type VII collagen in inflammatory bowel disease. J Cell Mol Med. 2010;14:2393–2403.
161. Gluck M, Kayne A. Acquired epidermolysis bullosa and Crohn's disease. Gastrointest Endosc. 2003;57:563–564.
162. España A, Sitaru C, Pretel M, et al.. Erythema gyratum repens-like eruption in a patient with epidermolysis bullosa acquisita associated with ulcerative colitis. Br J Dermatol. 2007;156:773–775.
163. Hughes AP, Callen JP. Epidermolysis bullosa acquisita responsive to dapsone therapy. J Cutan Med Surg. 2001;5:397–399.
164. Arora KP, Sachdeva B, Singh N, et al.. Remission of recalcitrant epidermolysis bullosa acquisita (EBA) with colchicine monotherapy. J Dermatol. 2005;32:114–119.
165. Maize JCJ, Cohen JB. Cyclosporine controls epidermolysis bullosa acquisita co-occurring with acquired factor VIII deficiency. Int J Dermatol. 2005;44:692–594.
166. Kowalzick L, Suckow S, Ziegler H, et al.. Mycophenolate mofetil in epidermolysis bullosa acquisita. Dermatology. 2003;207:332–334.
167. Sadler E, Schafleitner B, Lanschuetzer C, et al.. Treatment-resistant classical epidermolysis bullosa acquisita responding to rituximab. Br J Dermatol. 2007;157:417–419.