Systemic lupus erythematosus associated with myasthenia gravis, pemphigus foliaceus and chronic thyroiditis after thymectomy

A 65‐year‐old woman had undergone a thymectomy for thymoma and 1 year after surgery she developed scattered erosive erythema with scaling and crusting. Examination findings exhibited the elevation of anti‐dsDNA antibody, anti‐desmoglein 1 antibody, anti‐acetylcholine receptor antibody and anti‐thyroglobulin antibody. A skin biopsy showed intraepidermal blisters containing neutrophils and acantholytic keratinocytes and direct immunofluorescence revealed the deposition of immunoglobulin G in the epidermis and on the basement membrane. These findings indicated the presence of systemic lupus erythematosus (SLE), myasthenia gravis, pemphigus foliaceus and chronic thyroiditis. Only 1% of SLE patients have three other autoimmune diseases according to previous publications. Our case is rare because she suffered four autoimmune diseases after the thymectomy.