Dermatitis herpetiformis (DH) is an unusual autoimmune cutaneous eruption related to gluten sensitivity. Affected patients commonly develop intensely pruritic inflammatory papules and vesicles on the forearms, knees, scalp, or buttocks. The majority of patients with DH have an associated gluten-sensitive enteropathy (celiac disease) as well. In most of these patients, the enteropathy is asymptomatic.
Panel test
- Immunogenetics:
- Increased incidence of HLA-A1/B8/DR3/DQw2 and associated organ- specific autoimmune disease.
- Immunopathology:
- DIF on the skin biopsy shows typical granular IgA deposits on the dermal papillae.
- Jejunal/duodenal biopsies will often show features of coeliac disease even in the absence of clinical symptoms.
- Autoantibodies:
- IgA endomysial or tissue transglutaminase antibodies will be positive.
comments: Gluten-free diet will eventually lead to resolution of the rash.
Resistant cases may require treatment with dapsone, having first excluded G6PD deficiency (monitor all patients for haemolysis and methaemoglobinaemia.
References:
- Salmi TT, Hervonen K, Kautiainen H, et al. Prevalence and incidence of dermatitis herpetiformis: a 40-year prospective study from Finland. Br J Dermatol 2011; 165:354.
