[Dermatitis herpetiformis occuring in patients with celiac disease in childhood]

Dermatitis herpetiformis (DH) is a chronic papulovesicular immune-mediated disorder associated with gluten-sensitive enteropathy. We report eight cases in which DH appeared many years after celiac disease (CD) in child.

The diagnosis of CD was based on histological features of total or subtotal villous atrophy, full remission after withdrawal of gluten from the diet, and eventually circulating antibodies (IgA gliadin, antireticulin and antiendomysium) at the time of diagnosis and their disappearance under gluten-free diet. The diagnosis of DH was made from clinical findings, histological examination of the involved skin and direct immunofluorescence microscopy of normal or perilesional skin. HLA class II typing was performed in five patients. DRB1, DQA1, DQB1 and DBP1 alleles were studied.

DH appeared between 3 and 22 years after the initial diagnosis of CD. Five patients did not show at that time any digestive symptoms. In three cases, a break in the gluten-free diet or a recent revival of the normal diet preceded the rash. In only one case, DH appeared while the patient was under gluten-free diet. In three patients, the rash appeared many years after the gluten-free diet had been stopped. Phenotype DR3 and/or DR7 of the celiac disease could be found in four of the five patients studied; three of them were found to bear DQW2. The DR2 allele was not found in any of the five tested patients.

These eight cases illustrate the absence of precise nosological barrier between gluten-sensitive enteropathy of the DH and that observed in CD. The presence of the DR7 allele, and especially the absence of the DR2 allele, could explain the particularly severe and symptomatic course of the enteropathy in these patients. The delay in the appearance of DH, after a very variable period of normal diet, could correspond to the necessary time for progressive accumulation of IgA (or immune complex IgA-gluten) in the skin after a digestive sensitization to gluten. The preventive role of gluten-free diet is thus probable.

CD and DH likely correspond to two different stages of the same disease, thus requiring a prolonged follow-up of both digestive and skin tissues. Long-term eviction of gluten to prevent eventual DH must be balanced with the demand and the cost of such a diet.