Boy With Muscle Weakness and Papules on His Hands

A 5-year-old boy under treatment with prednisone for viral myositis returned to the clinic with erythematous papules over his interphalangeal and metacarpophalangeal joints and an erythematous rash around the eyelids.

Electromyography showed high-frequency repetitive discharges, spontaneous fibrillations, and positive sharp waves.

His CPK level was measured at 1750 U/L and his aldolase at 60 U/L.

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