Author: Dr Ian Coulson, Consultant Dermatologist and Editor-in-Chief, 2022.
Edited by the DermNet content department
A 67-year-old man gives a six-week history of a progressive, itchy, and blistering eruption affecting his limbs. There has been no involvement of his mucous membranes. He has a 10-year history of Crohn disease.
There are blisters arranged in a ring — the so-called “string of pearls” sign, which is most often seen in this condition.
Perilesional immunofluorescence will show a linear band of IgA at the dermoepidermal junction, in contrast to the granular deposits of IgA seen in dermatitis herpetiformis. The blisters are sub-epidermal. As opposed to dermatitis herpetiformis, linear IgA disease is not associated with gluten enteropathy.
Linear IgA disease may be associated with solid cancers and lymphomas, inflammatory bowel disease, and rheumatoid disease. Several drugs have been implicated in initiating this condition.
Treatment of this condition involves the use of potent topical steroids, but oral steroids combined with oral dapsone are usually required.
