Dermatitis herpetiformis. IV. Medicamenteuze behandeling

In this article some aspects of the drug therapy of dermatitis herpetiformis (DH) are discussed. It is recommended to treat DH patients with dapsone (preferably in combination with a gluten free diet) after excluding contraindications such as glucose-6-phosphatedehydrogenase deficiency. The initial dosis of dapsone is 50-100 mg. In case of insufficient response after 1-2 weeks, the dosis can stepwise be increased with 50 mg until the cutaneous manifestations are adequately suppressed. When the skin symptoms are completely inactive, it may be attempted to gradually decrease the dosis of dapsone to the lowest effective dosage. Both the dosis reduction and its speed should be individualized. Dapsone causes adverse effects in a considerable number of patients. Some side effects are frequent and dose-related (haemolysis, methaemoglobinemia), others are serious (agranulocytosis, dapsone hypersensitivity syndrome), but occur less frequently. Always, the lowest effective dosage should be sought. In cases of symptomatic methaemoglobinemia, the addition of cimetidine 400 mg t.i.d. may be attempted to decrease the amount of methaemoglobin. A scheme for laboratory check-up is presented. In patients with dermatitis herpetiformis in who dapsone is contraindicated, causes unacceptable side effects or is ineffective, a therapeutic trial with sulphapyridine or sulphamethoxypyridazine may be tried.