No Mucosal Involvement in a Patient with Paraneoplastic Pemphigus Associated with Thymoma and Myasthenia Gravis

A 44-year-old Korean woman with myasthenia gravis (MG) and invasive thymoma presented with paraneoplastic pemphigus (PNP) and alopecia areata, but notably without mucosal involvement. She initially showed symptoms of diplopia and ptosis, which improved with methylprednisolone treatment. Later, she experienced muscle weakness and alopecia. Diagnostic tests confirmed MG and revealed a mediastinal mass consistent with thymoma. Biopsy and immunofluorescence studies indicated nonscarring alopecia with IgG and C3 deposits. Immunoblotting detected envoplakin and periplakin, but no anti-desmoglein antibodies were found. This case was unique due to the absence of mucosal involvement in PNP.