|
| Fig. 37.9 Dermatitis herpetiformis. A, Papules and vesicles with excoriations in a symmetrical distribution on the elbows and knees are typical of dermatitis herpetiformis. B, Excoriations and secondary infection due to intense itching and scratching are common. Lesions may be confused with scabies and folliculitis. C, Direct immunofluorescence of lesional skin in dermatitis herpetiformis showing granular deposits of IgA in the tips of dermal papillae. |
Dermatitis herpetiformis (DH) is an immunobullous skin disease. Onset typically occurs between 20 and 40 years of age and affects men in a 2:1 ratio to women. Patients develop intensely itchy papules, papovesicles, and occasionally tense blisters in a grouped (herpetiform), symmetrical distribution over the scalp and posterior neckline, shoulders and back, elbows, knees, and the lumbosacral region (Fig. 37-9). Rarely, urticarial lesions without papulovesicles may be the only manifestation of the disease. Lesions on the palms are uncommon, and the mucous membranes are only rarely involved. Over 90% of patients will have histologic evidence of a gluten-sensitive enteropathy, ranging from increased intraepithelial lymphocytes to complete villous atrophy of the jejunum.
The disease in the skin and the intestinal tract (small intestine) is triggered by dietary gluten found in many grains (but not in rice, corn, or oats). There are usually no abdominal symptoms but an occasional patient may complain of bloating, cramping, and diarrhea. A diet completely free of gluten will clear the skin and intestinal tract lesions; however, this diet is difficult for many patients to maintain. The skin disease is characterized by the accumulation of polymorphonuclear neutrophils (PMNs) and granular deposits of IgA in the tips of the dermal papillae. These two findings are considered diagnostic of DH. In addition, most patients, as with celiac patients, show increased frequency of HLA-A1, HLA-B8, HLA-DR3, and HLA-DQw2 haplotypes. Current research indicates that epidermal transglutaminase 3 is the autoantigen in DH, which when coupled with gluten and a predisposition to gluten sensitivity, cross reacts with IgA antibodies.
Patricio P, Ferreira C, Gomes MM, Filipe P: Autoimmune bullous dermatoses: a review, Ann N Y Acad Sci
1173:203–210, 2009.
Zone JJ: Skin manifestations of celiac disease,
Gastroenterol 128:S87–S91, 2005.
