Crohn’s disease (CD) is a chronic disorder of unknown etiology characterized by granulomatous inflammation of the gastrointestinal tract. Cutaneous tissue involvement may be one of the extraintestinal manifestations of the disease. Cutaneous Crohn’s (CC) may develop from systemic focus through contiguous or metastatic spread. CC may be speculated as a possible cutaneous marker of latent underlying inflammatory bowel disease (IBD), and may precede, present simultaneously, or even manifest years later to the intestinal CD. CC without clinically and endoscopically apparent bowel involvement is a rare possibility and is sparsely found in the literature. CC has a variable clinical presentation and usually presents as nodules, plaques, purple perifollicular papules, perianal and peristomal fissures, ulcers and fistulae, and deep linear slits. Clinical presentation of CC may simulate other granulomatous disorders like cutaneous tuberculosis or nongranulomatous diseases like hidradenitis suppurativa (HS), especially when it involves apocrine glands bearing areas of the body. HS is a chronic inflammatory disease of apocrine glands characterized by follicular occlusion and secondary development of papulonodular lesions, abscesses, polyporous comedones, and sinus and fistula formation. HS is found to be independently associated with IBD, especially CD, but its association with CC when there is a lack of bowel involvement has not been described. We are hereby reporting a clinical scenario where there is co-occurrence of CC and HS without evidence of bowel involvement either clinically or endoscopically.
A 29-year-old unmarried male presented with complaints of painful papulonodular lesions and discharging sinuses predominantly involving the scrotum and perianal region since puberty. Detailed clinical history and previous clinical records confirmed the diagnosis of HS with remitting and relapsing course. The disease course was stable on finasteride and isotretinoin with intermittent flares managed with oral antibiotics for many years. The symptoms exacerbated in the last 2 years and were refractory to the above treatment. Treatment history also revealed a trial of antituberculosis treatment for 9 months without any improvement. For the last 2 years, the patient also noticed development of multiple deep linear slits over the scrotal skin for which he was apprehensive and seeked consultation in our outpatient department. On clinical examination, polymorphic cutaneous lesions were present over the scrotal, perianal, and pubic areas including papulonodules, discharging sinuses, bridging scars, and polyporous comedones and multiple knife-cut linear slits. The scrotum was edematous with maceration of the overlying skin [Figures 1 and 2]. The deep linear slits had multiple sinuses studded at their base with discharge of seropurulent exudate. Regional inguinal nodes were bilaterally enlarged, discrete and nontender on palpation without changes in the overlying skin. Past history was unrevealing for any dysuria, profuse urethral discharge, or genitoulcerative disease. The other apocrine gland-bearing sites except groin were spared. There was no history of abdominal pain, diarrhea, and hematochezia. The patient had no complaints related to joints and eyes. Another systemic examination was unrevealing. Despite previous clinical and histopathological evidences [Figure 3], which were highly suggestive of HS, the patient was re-investigated keeping in mind atypical course of HS, cutaneous tuberculosis, watering can perineum, and CC as our differentials. The patient underwent a battery of investigations (complete blood count, urine routine examination, liver and kidney function tests, and chest X-ray) with no significant abnormalities. Serum hepatitis B surface antigen, hepatitis C virus, HIV ELISA, venereal disease research laboratory, and treponema pallidum hemagglutination assay were nonreactive. Urine culture was sterile. Ultrasonography of the scrotum and sigmoidoscopy revealed no abnormalities at this stage. Repeat biopsy from the cutaneous lesions showed perifollicular and perivascular noncaseating granulomas with heavy infiltrate of neutrophils, epithelioid histiocytes, lymphocytes, and occasional plasma cells predominantly in the papillary and reticular dermis with intact pilosebaceous unit which was consistent with the diagnosis of CC [Figure 4]. The patient was also advised a colonoscopic-guided gastrointestinal biopsy for detecting microscopic involvement by CD, but consent was denied. On the basis of clinical judgment and histopathological findings, we made the diagnosis of CC associated with HS without apparent involvement of the alimentary canal.
The patient was managed with antibiotics, high-dose steroids, and azathioprine along with scrotal support and maintenance of local hygiene. The patient showed improvement in the symptoms and was satisfied with the response 4 weeks after initiation of the treatment and was further planned for adalimumab but denied consent.
CD is a chronic, granulomatous multisystem disorder with a prevalence of 1.3–5.3/100,000 population that occasionally affects cutaneous tissue. CC in isolation without primary focus in the gastrointestinal tract is a rare possibility and a diagnosis of exclusion. The common disorders that should be contemplated as close differential of CC are cutaneous tuberculosis, HS, and watercan perineum as complication of genitourinary infections. Our patient was a known case of HS, and the stable course of disease was interrupted with severe flare in symptoms along with appearance of new findings of deep linear knife-cut slits over the scrotal and perianal areas. After excluding close differentials on the basis of clinicolaboratory profile, we considered the diagnosis of CC. As per a recent report published, knife-cut linear slits are regarded as an important clinical clue for CC. Cutaneous manifestation of CD may be classified as specific lesions based on histopathological findings consistent with CD or reactive lesions where histopathology departs from classic presentation. Specific lesions typically occur either contiguous or noncontiguous to underlying gastrointestinal focus. There is no relationship between CC and the severity of CD. Interestingly, an extraintestinal manifestation including specific lesions of CD may precede the formal diagnosis of CD in about 25% of cases. The most common sites include the intertriginous and flexural areas of the body, with a predilection for the lower extremities, which is similar to the common site for HS, thereby acting as a confounding factor in diagnosis. Hence, it is suggested that in specific cutaneous lesions endoscopic evidence of underlying focus should be searched. Unfortunately, endoscopy was unrevealing in our case. As cutaneous manifestation of CD may predate GI involvement in occasional cases, mere absence of endoscopic or clinical evidence may not outrightly exclude the diagnosis of CC. Based on the extensive clinicolaboratory findings along with negative endoscopic findings of CD, it is justified that the is isolated CC without bowel involvement.
It has been hypothesized that the presence of a circulating antigen deposited in the skin triggers a type IV hypersensitivity reaction, mediated by T-lymphocytes which lead to the formation of granulomatous lesions. Histopathology is a key for unlocking the reality in such redundant clinical presentations with several close possibility. The probability of noncaseating epithelioid granuloma occurring in a case of HS is very low. Similarly, polyporous comedones in CC are seen very rarely. In our case, we have both these findings simultaneously which lead us to believe this to be a case of HS superimposed with CC over a period of time.
Principi et al. have found the association of CD and HS to be 17.3% in their study. However, it is difficult to find a documented association of HS with CC solely in medical literature. In addition to this, our case also emphasizes that CC may manifest without involvement of the gastrointestinal tract. Our patient was advised for scheduled 6 monthly endoscopic examinations by a gastroenterologist for detection of features related to CD at the earliest in the gastrointestinal tract.
The association of HS and CC is a rare presentation and CC is a diagnosis of exclusion when there is a lack of gastrointestinal involvement. In such cases where cutaneous manifestations predate intestinal manifestations, histopathology is key in diagnosis and it is essential to follow the patient for impending gastrointestinal involvement. In such cases of HS with an atypical course, a high index of suspicion should be kept for CC.
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