Linear IgA disease associated with lymphocytic colitis

A 66-year-old woman presented with a bullous skin eruption and chronic diar rhoea, Lesional skin showed subepidermal blistering, and direct immunofluor escence of perilesional skin revealed linear deposits of IgA at the dermoep idermal junction, establishing a diagnosis of linear IgA disease (LAD). Chr onic watery diarrhoea complicated by substantial loss of body weight preced ed the skin eruption for several months. On endoscopy, the colon appeared m acroscopically normal. On histology, the colon mucosa showed increased numb ers of intraepithelial lymphocytes and infiltrates of mononuclear cells in the lamina propria, indicative of lymphocytic colitis. Treatment with methy lprednisolone and dapsone led to complete clearing of the bullous skin erup tion and marked improvement of the patient's diarrhoea. Gastrointestinal di sorders such as lymphocytic colitis have rarely been reported in patients w ith LAD. Whether the simultaneous occurrence of these two diseases is coinc idental or due to related pathogenetic mechanisms remains to be seen.