Various forms of pemphigus have been reported to occur with myasthenia gravis (MG), with and without thymoma. We described two cases of pemphigus vulgaris associated with MG without thymoma. Case 1. A 44 year-old woman presented with 3 years history of pemphigus vulgaris. Three years later, she developed myasthenic symptoms with elevated level of anti-acetylcholine receptor (AChR) antibodies - 5.2 nmol/L. She was thymectomised and we revealed only hyperplastic thymus. Case 2. A 64-year-old woman had a general fatigue and intermittent double vision. She was diagnosed as MG three years later. Two months before she diagnosed as MG, she had pruritic erythematous, erosive and bullous lesions on her body and extremities. Oral prednisolon, pyridostigmine bromide and azathioprine or cyclophosphamide didn't adequately control MG and pemphigus in our patients, so they received intravenous immunoglobulins of 0.4 g/kg for 5 consecutive days. After that therapy, our patients markedly improved.
Conclusion: The precise pathological mechanisms of the association between pemphigus and MG are not fully understood. The thymus has been suggested to be a possible common origin of autoimmune response in these disorders.