A case of vitiligo vulgaris showing a pronounced improvement after treatment for myasthenia gravis.

This is a report of a 64 year-old male patient whose myasthenia gravis (MG) was accompanied by vitiligo vulgaris. Depigmentation of the face, trunk, and hands was noted. He was diagnosed with vitiligo vulgaris according to macroscopic findings and a skin biopsy. He was also found to have blepharoptosis, and proximal dominant muscle weakness of the extremities. He was anti-acetylcholine receptor antibody-positive, with repetitive nerve stimulation showing a waning phenomenon and chest computed tomography showing invasive thymoma, which led to the diagnosis of generalised MG. His myasthenic symptoms were relieved by the use of steroids and the removal of the thymoma. His vitiligo vulgaris began to improve a month after the relief of myasthenic symptoms. Such improvement was pronounced during the next several months. The clinical or immunological relationship between MG and vitiligo vulgaris is still not known, but these findings might indicate clinical correlation between MG and vitiligo vulgaris.