[Fatal interstitial lung disease and pneumocystis during dermatomyositis associated with anti-MDA5 antibodies]

Dermatomyositis (DM) in an auto-immune inflammatory myopathy with skin lesions, and, occasionally, organ involvement. Herein, we report a case of DM during anti-MDA5 antibody therapy associated with interstitial lung disease (ILD) and pneumocystosis.

A 64-year-old woman was hospitalized for impairment of her general health and skin lesions. Dermatological examination revealed classic signs of DM associated with hyperkeratotic papules on the palm creases. This led us to suspect DM with anti-MDA5 antibodies, which was subsequently confirmed by immunologic tests. We also noted dysphonia, exertional dyspnea and proximal muscles weakness. Despite early corticosteroid therapy, combined later with azathioprine, the patient's dyspnoea worsened; one month later, sudden pulmonary decompensation resulted in her admission to intensive care. A chest scan showed evidence of ILD and infectious signs, and the bronchoalveolar lavage was positive for Pneumocystisjiroveci. Despite treatment of this opportunist infection with cotrimoxazole and intensified immunosuppression, the patient died in intensive care.

Anti-MDA5 antibodies are associated with a specific clinical phenotype and a high degree of risk that should alert the dermatologist to the high likelihood of ILD having a poor prognosis. Associated clinical signs are erythematous, hyperkeratotic or ulcerated papules on the palm creases, as well as fingertip or periungual ulcerations or digital necrosis. This situation is associated with a high risk of pneumocystosis. However, no recommendations concerning prophylaxis are currently available.