Erythroderma and extensive poikiloderma – a rare initial presentation of dermatomyositis: a case report

BACKGROUND Dermatomyositis is a humoral-mediated inflammatory myopathy with symmetrical proximal muscle weakness and dermatological manifestations such as Gottron's papules, heliotrope rash, periungual abnormalities, and flagellate erythema. Erythroderma is a severe and potentially life-threatening dermatological condition with diffuse erythema and scaling involving more than 90% of the skin surface area. Poikiloderma vasculare atrophicans refers to mottled hyperpigmentation and hypopigmentation of the skin with in-between telangiectases and areas of atrophy and is considered a variant of mycosis fungoides. Poikilodermatomyositis is the term given to the condition with poikiloderma and inflammatory myopathy. Only a few cases are reported on erythroderma in dermatomyositis and poikilodermatomyositis. Erythrodermal pattern of dermatomyositis transforming into poikilodermatomyositis is a recognized rare manifestation of dermatomyositis and we could find only one case report in the literature. CASE PRESENTATION A 53-year-old Sri Lankan woman presented with intermittent fever of 5 months' duration with erythroderma. Later she developed progressive, symmetrical proximal muscle weakness. Following a short course of small dose steroids, erythroderma settled but changed to extensive poikiloderma involving more than 90% of her skin with her face being relatively spared. She had an early heliotrope rash, shawl sign, and Gottron papules. Electromyography and muscle biopsy were supportive of inflammatory myositis and skin biopsy showed evidence of dermatomyositis. Inflammatory markers and muscle enzymes were also elevated. Autoimmune antibodies and myositis-specific autoantibodies were negative. She was started on orally administered prednisolone 1 mg/kg per day with methotrexate 10 mg once a week and had a good response to treatment with resolution of the skin condition and improvement of muscle power. Imaging studies, endoscopies, and tumor markers did not reveal any malignancy. CONCLUSIONS This case illustrates a rare presentation of dermatomyositis initially presenting as fever, erythroderma, and proximal muscle weakness and later developing poikiloderma involving more than 90% of the skin. It is important to be aware of this rare presentation to avoid misdiagnosis. With the currently available literature it is not possible to conclude that erythroderma is a bad prognostic factor in dermatomyositis or a predictive factor for a malignancy. Patients have a good response to steroids with a combination of immunosuppressants.