[A patient with limb-girdle type myasthenia gravis and atopic dermatitis, both of which improved after thymectomy]

We herein report a patient with myasthenia gravis (MG) and atopic dermatitis (AD). Heretofore, there have been no reports of patients with MG and AD. Nine years ago, a 25-year-old man noted muscle weakness of upper and lower extremities on physical labor, and the muscle weakness was gradually exacerbated. Two years ago, he noted acute skin eczema with itching on his hands and feet. Neurological examination revealed mild left ptosis, facial muscle weakness and proximal muscle weakness of upper and lower extremities, but no diplopia, ophthalmoplegia or dysphagia. Although anti-nicotinic acetylcholine receptor antibody was negative, edrophonium test was positive and 54% waning in the thenar muscles was observed on Harvey-Masland test. Thus, he was diagnosed as limb-girdle type MG. IgE level in his serum elevated (1,818 U/ml). After thymectomy, the muscle weakness markedly improved as well as waning in the thenar muscles (11%). Simultaneously, AD markedly improved and serum IgE level was decreased (1,245 U/ml). Thus, MG and AD in this case may be derived from some common immunological aberrancy in the thymus.