Dermatomyositis and myastenia gravis: An uncommon association with therapeutic implications.

The association of dermatomyositis with myasthenia gravis (MG) is uncommon, having been reported so far in only 26 cases. We report the case of a 69 year-old man diagnosed with MG two years ago and currently treated with piridostigmyne. The patient developed acute proximal weakness, shoulder pain and elevated creatine-kinase (CK). He also developed generalized facial erythema and Gottron's papules. Laboratory tests showed positive antinuclear and anti-Mi2 antibodies. Further analysis confirmed CK levels above 1000 U/l. The clinical management of the patient and the therapeutic implications derived from the coexistence of both entities are discusssed.