A Case of Ulcerative Colitis that Developed during Treatment for Linear IgA Bullous Dermatosis

Abstract

A 56-year-old man was referred to our department with erythema and blisters on the trunk and limbs. We diagnosed linear IgA bullous dermatosis, based on the deposition of IgA along the dermoepidermal junction. We administered oral diaphenylsulfone ; however, new blisters appeared. He was admitted to our department for additional oral prednisolone administration. During hospitalization, thoracoabdominal computed tomography and upper and lower endoscopies were performed to search for malignant tumors. Although rectal vascular permeability was observed, it was not typical of ulcerative colitis. The dose of prednisolone was reduced on an outpatient basis, but exacerbation of blood in the stool and worsening of the skin rash occurred. After another lower endoscopy, ulcerative colitis was diagnosed. After the treatment of ulcerative colitis began, the rash subsided. Linear IgA bullous dermatosis is associated with ulcerative colitis, and ulcerative colitis often precedes the onset of the disease. In our case, linear IgA bullous dermatosis preceded the onset of ulcerative colitis. This sequence may have been obscured by the initiation of prednisolone treatment before the endoscopy, which masked the underlying condition. Skin Research, 24 : 157-161, 2025