Protective effect of gluten-free diet against development of lymphoma in dermatitis herpetiformis.

A retrospective study of 487 patients with dermatitis herpetiformis showed that lymphoma developed in eight patients, the expected incidence being 0.21 (standardized registration ratio 3810). All lymphomas occurred in patients whose dermatitis herpetiformis had been controlled without a gluten-free diet (GFD) or in those who had been treated with a GFD for less than 5 years. The results are suggestive of a protective role for a GFD against lymphoma in dermatitis herpetiformis and give further support for advising patients to adhere to a strict GFD for life.