[Papular mucinosis associated with myopathy].

BACKGROUND

Papular mucinosis is an uncommon condition sometimes associated with myopathy as in our case.

METHODS

A 54-year-old woman presented several disseminated pruriginous papules that spread progressively. Histopathology of a skin biopsy showed mucine deposits and fibroblasts in the derma. Serum monoclonal lambda IgG was evidenced. The patient complained of weakness of the proximal muscles and dysphagia. Serum creatine phosphokinase was moderately elevated and the electromyography showed a typical myogenic pattern. Histopathology of a muscle biopsy disclosed a polymyositis aspect without mucine deposits. The patient was given prednisone. The skin lesions regressed totally with no modification of the muscle deficit.

CONCLUSIONS

Myopathy associated with papulous mucinosis generally presents as a proximal deficit with dysphagia. Myalgia and amyotrophy are exceptional. Moderate serum myolysis is often evidenced. The electromyogram shows a myogenic pattern. The pathophysiology of this condition remains unclear, but the association with papulous mucinosis does not appear to be fortuitous due to its frequency. No standard treatment has been established. General corticosteroid therapy is generally effective and methotrexate, melphalan, isotretinoine and D-penicillamine have given good results in a few cases.