Celiac disease evolving into dermatitis herpetiformis in patients adhering to normal or gluten-free diet.

OBJECTIVE: Dermatitis herpetiformis (DH) is a cutaneous form of celiac disease affecting ∼ 17% of celiac disease patients. The aim was to determine how often celiac disease precedes the development of DH, and what is the impact of gluten-free diet (GFD) in this phenotype change. MATERIAL AND METHODS: Our prospectively collected DH series from 1970 comprised 514 patients. We analyzed all DH patients who at least 2 years earlier had been diagnosed with celiac disease. DH diagnosis was confirmed by showing immunoglobulin A deposits in dermis. Serological and small bowel mucosal findings were analyzed, and the strictness of GFD treatment before and after the diagnosis of DH was evaluated. RESULTS: Twenty (4%) DH patients had a prior diagnosis of celiac disease. The median time interval between celiac disease and DH detection was 9.5 years. Before DH appeared 4 patients had been on a normal gluten-containing diet, 10 had dietary lapses on a GFD, and 6 were on a strict GFD. Celiac autoantibodies were positive in 7 out of 19 patients, and 5 out of 7 undergoing small bowel biopsy had partial villous atrophy. Following DH diagnosis the rash was controlled after a median of 6 months on a strict GFD. CONCLUSIONS: Patients with celiac disease may develop DH by time. This is most often an indicator of poor adherence to GFD, and a rigorous dietary intervention is necessary. In the majority of cases, DH will be detected without prior celiac disease diagnosis, but the physicians should recognize this phenotype alteration.