Dermatomyositis manifests with proximal muscle weakness and characteristic skin changes, including the Gottron sign and heliotrope periorbital rash. However, it may also present with various skin manifestations including erythroderma, periungual abnormalities, flagellate erythema on the trunk, psoriasiform changes on the scalp, calcinosis cutis, a roughening and cracking of the skin of the tips and lateral aspects of the fingers (mechanic's hands), a diffuse flat erythematous lesion occurring over the chest and shoulders (Shawl sign), and a V-shaped distribution over the anterior neck and chest (V sign).1 Scleroderma is a relatively rare connective tissue disorder characterized by skin fibrosis or hardening, obliterative vasclulopathy presenting with Raynaud phenomenon, and autoantibodies including anti–Scl-70 and anticentromere. Scleroderma-like disorders (SLDs) comprise a wide spectrum of heterogeneous diseases characterized by sclerosis of the dermis, subcutis, and sometimes the underlying soft tissues and bone. The hallmark of this group of diseases is skin thickening as in systemic sclerosis, and some are associated with autoantibodies and/or autoimmune conditions. SLD can present with histologic features of an excessive local accumulation of collagen and other extracellular matrix components.2 However, unlike scleroderma, most SLDs including scleromyxedema, scleredema, and nephrogenic systemic fibrosis can present with extensive interstitial mucin deposition pathologically.3 Previous reports of dermatomyositis showed that it might overlap with features of other connective tissue disorders, particularly scleroderma, which was called a dermatomyositis–scleroderma overlap syndrome.4,5 However, there has been no previous report to show focal scleroderma-like skin changes in dermatomyositis. In this study, we present a patient with dermatomyositis, confirmed by muscle biopsy, who presented with unusual focal scleroderma-like skin changes.
A 41-year-old woman presented with a 1-year history of muscle weakness and pain. The patient had difficulty raising her arms above the shoulder and swallowing solid foods. She denies the skin rash in her fingers or periorbital areas or the discoloration of the skin of her hands when she was exposed cold temperature. She had a history of hypertension, and there was no familial history of muscle weakness. Social history was unremarkable.
Vital signs and general examination were normal except for mild alopecia, the skin atrophy and hardening over the left temporal areas (Fig. 1A), and symmetrical atrophy and hardening over the lateral arms, and posterior shoulders (Fig. 1B). Skin was adherent to underlying tissues over the atrophied areas. The size of firm skin was 11 × 16 cm and 6 × 16 cm in the left and right arms individually, 5 × 14 cm and 6 × 13 cm in left and right back individually, and 6 × 6 cm in the left temporal area. There were no Gottron sign, Gottron papules, or heliotrope periorbital rash or edema. Neurologic examination revealed normal speech, mentation, and cranial nerves. Muscle strength was normal except for mild weakness in the gluteus medius, handgrip bilaterally at 4/5, and moderate muscle weakness in deltoids and shoulder adductors bilaterally at 4/5. Muscle tone was normal. Deep tendon reflexes were slightly decreased and symmetric. Sensory examination was intact in all modalities. Gait was normal. Comprehensive metabolic panel including glucose, urea nitrogen, creatinine, alanine aminotransferase, and aspartate aminotransferase were all within normal limits. Serum creatine kinase is within normal limit at 59 (normal range 1–165). A muscle biopsy showed perifascicular fiber atrophy (Fig. 1C), inflammation (Fig. 1D), and deposition of complement in capillaries in the C5b-9 staining and increased activity of alkaline phosphatase (data not shown).
Focal scleroderma was highly suspected given the typical findings of skin hardening. Extensive blood workup for scleroderma and other connective tissue diseases, including serum C-reactive protein and fluorescent antinuclear antibody, ribonucleoprotein antibody, Smith antibody, double-stranded DNA antibody, rheumatoid factor, anticentromere body, and Scl-70 antibody, were all within normal limits. Serum C-reactive protein was within normal limits. Serum human immunodeficiency antibodies 1 and 2 were also negative. A skin biopsy in the lateral arm showed scattered menalocytes (Fig. 2A), perivascular lymphocytic inflammation (Fig. 2B), and increased mucin staining in the reticular dermis without evidence of severe fibrosis such as thick bundles of collagen (Fig. 2C).
The patient was initially treated with 30 mg/d of prednisone, but her lesions continued to expand. Symptoms came under control with 60 mg of prednisone daily. Oral methotrexate 10 mg/wk was added because of side effect of steroid. She developed a new pectoral lesion on prednisone reduction to 30 mg/d, and methotrexate dose was increased to 15 mg/wk. Further reductions in prednisone caused disease reactivation, necessitating methotrexate dose increment. Her proximal arm weakness and swallowing difficulties improved and hardening over the lateral arms, and posterior shoulder regions were getting softer for over a year on methotrexate 25 mg/wk and now on tapering prednisone to 10 mg/d. Her last flare-up was on methotrexate dose reduction to 20 mg/wk.
Dermatomyositis manifests with proximal muscle weakness and a skin rash including a typical Gottron sign and heliotrope periorbital skin changes. However, it may also present with other skin manifestations. We report a patient who presented with proximal muscle weakness without typical skin changes of dermatomyositis. Subsequent muscle biopsy revealed a perifascicular fiber atrophy, a characteristic finding of dermatomyositis. The patient developed scleroderma-like skin changes characterized by symmetrical atrophy and hardening of focal skin and muscle over the lateral upper arms and posterior shoulders, and the left temporal and pectoral areas, which improved with immunotherapy. Previous reports revealed that dermatomyositis might overlap with features of other connective tissue diseases, such as scleroderma, systemic lupus erythematosus (SLE), mixed connective tissue disease, and, less often, rheumatoid arthritis and Sjögren syndrome.4,5 To the best of our knowledge, there have been no previous reports of a focal scleroderma-like skin changes in dermatomyositis.
In our patient, focal scleroderma was highly suspected initially, given the similar skin changes including skin hardening and atrophy of subcutaneous tissue. However, the extensive workup for scleroderma, including antinuclear, anti–Scl-70, and anticentromere antibodies, was negative. Furthermore, skin histology helped to determine that she had SLD instead of scleroderma. Similar to scleroderma, SLD can also manifest tissue fibrosis with thickened disorganized collagen bundles and an increased number of fibrocytes. However, unlike scleroderma, most SLDs including scleromyxedema, scleredema, and nephrogenic systemic fibrosis can present with extensive interstitial mucin deposition.4 Our patient showed distinct pathologic characteristics, including increased interstitial mucin accumulation, scattered melanophages, and perivascular inflammation without fibrosis. The increased interstitial mucin accumulation in our case appeared like typical SLD and differentiates it from scleroderma. However, the absence of fibrosis and the presence of hyperpigmentation also seems to be different from the cases of SLD described previously.2,3
SLE and dermatomyositis can cause cell-poor interface dermatitis with a sparse infiltrate of inflammatory cells presenting along the dermoepidermal junction.6 Both could result a in striking dermal mucin deposition, which is a helpful distinguishing feature from other cell-poor interface dermatitis including erythema multiforme, graft-versus-host disease, morbiliform viral exanthema, and morbiliform drug reaction. On histology, subacute cutaneous lupus erythematosus demonstrates suprabasilar exocytosis of lymphocytes with no significant deep perivascular infiltrate.5 However, in contrast to subacute cutaneous lupus erythematosus, our case showed distinct pathologic changes such as scattered menalocytes and perivascular lymphocytic inflammation. Furthermore, the negative fluorescent antinuclear antibody, anti–double-stranded DNA, anti-Smith antibodies, and perifascicular fiber atrophy in the muscle biopsy in our case were against SLE.
The distinct pathologic findings in our case are similar to the findings of reticular erythematous mucinosis (REM), which is a rare form of cutaneous mucinosis and could present with increased mucin in skin biopsy. REM most often affects middle-aged women. Skin biopsies in REM show pathologic skin changes similar to our case, including a superficial to mid dermal perivascular lymphocytic infiltrate associated with dermal mucinosis without proliferation of fibroblasts.7 However, in contrast to our case, REM presents as erythematous infiltrated plaques characteristically occurring on the midline of the back and chest and is also called “midline mucinosis” or “plaque-like cutaneous mucinosis.”
In summary, we present a case of dermatomyositis, confirmed by muscle biopsy, and she had unusual focal scleroderma-like skin changes clinically and REM-like changes pathologically. Our case did not fit typically into any of the known cases of SLD of the skin described to date. The particular syndrome of dermatomyositis with focal scleroderma-like skin changes and REM-like pathology findings represent a new variant of skin lesions of dermatomyositis.
The authors thank Rachel Young for critical reading of the article.
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