Pemphigus foliaceus exacerbated by radiation, in association with myasthenia gravis

Pemphigus foliaceus (PF) is a sporadic autoimmune blistering disease of unknown etiology. The production of immunoglobulin G4 antibodies against desmoglein-1 is responsible for the clinical manifestation of PF. We present a case of a woman with a recent diagnosis of myasthenia gravis (MG), who was also recently treated with radiation therapy for breast cancer. The clinical exam, supported by biopsy and direct immunofluorescence, were consistent with PF. We present this case to increase the awareness of the potential exacerbation or induction of PF with radiation, and of the association of PF and myasthenia gravis. Only five prior cases of radiation-exacerbated or radiation-induced PF have been reported in the literature to date. Furthermore, the co-existence of the autoimmune entities of myasthenia gravis and PF has been reported in the literature in only 9 cases and was also noted in this patient.