Anaemia in Dermatitis Herpetiformis.

Summary— Forty-three patients being treated with dapsone for dermatitis herpetiformis were studied to determine the prevalence and mechanisms of anaemia in this condition. Anaemia was more common than in a comparable normal control group although it was usually mild. Most patients had evidence of drug-induced haemolysis which was dose related and this was the most important cause for anaemia. Malabsorption did not seem to be a significant factor in the development of anaemia. The incidence of iron deficiency was no greater than in the controls, despite urinary iron loss. Five patients had low levels of serum B12, of whom 3 had pernicious anaemia. The incidence of low serum folate levels was less than that found by other workers although serial estimations revealed considerable fluctuations. The possibility that patients with dermatitis herpetiformis are more susceptible to the haemolytic effects of dapsone and the possible effects of dapsone on oxygen transport are discussed.