Fibrillar-type dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is a pruritic papulovesicular disease that is relatively common in Caucasian populations, and was first reported by Louis Duhring. It is characterized by granular IgA deposition in the dermal-epidermal junction and gluten-sensitive enteropathy (GSE) associated with human leukocyte antigen-DQ2/DQ8 haplotype. In contrast, DH is rare in Japan, and Japanese DH patients occasionally show unique features, including a high frequency of fibrillar IgA deposition in the papillary dermis, and rare occurrence of GSE. We refer to this condition in Japanese patients as "fibrillar-type DH", while the DH that is typically observed in the Caucasian population is referred to as "granular-type DH". In patients with typical fibrillar-type DH, IgA antibodies to epidermal transglutaminase are the only antibodies detected. In addition, Th2-type cytokines, such as interleukin (IL)-4, IL-5 and IL-13, may be important in the development of skin lesions in fibrillar-type DH (especially in the infiltration of tissue by eosinophils), as in granular-type DH. The pathogenesis of fibrillar-type DH may differ from that of granular-type DH, which is dependent on gluten and in which IgA antibodies to tissue transglutaminase (the main antigen in GSE) are detected. We herein review the clinical, histological, and immunological findings of fibrillar-type DH.

The incidence and prevalence of dermatitis herpetiformis in Utah.

BACKGROUND AND DESIGN: The incidence and prevalence of dermatitis herpetiformis has never been formally evaluated in any area of the United States. Several northern European studies have shown prevalence rates ranging from 1.2 per 100,000 to 39.2 per 100,000. The present study was performed to evaluate the incidence and prevalence of dermatitis herpetiformis in Utah. Information from 240 patients diagnosed with dermatitis herpetiformis was compiled from hospital records throughout Utah, as well as the sole private dermatopathologist in the state, and from the university referral center of the state. Criteria for inclusion in the study were a clinical diagnosis of dermatitis herpetiformis plus granular deposition of IgA in dermal papillae by direct immunofluorescence of uninvolved skin, or histopathologic findings consistent with the disease. Clinical diagnosis and response to dapsone alone was considered insufficient for inclusion in the study. On the basis of these criteria, as well as exclusion of non-Utah residents, 188 of the original 240 patients qualified for the study. RESULTS: The prevalence of dermatitis herpetiformis in Utah in 1987 was 11.2 per 100,000. The mean incidence for the years 1978 through 1987 was 0.98 per 100,000 per year. The mean age at onset of symptoms for male patients was 40.1 years, and that for female patients was 36.2 years. The male-female ratio was 1.44:1. CONCLUSIONS: This represents the first evaluation of the incidence and prevalence of dermatitis herpetiformis in the United States. These results are similar to those of the previous studies, probably because of Utah's largely northern European ancestry. This population base, plus a much smaller than average black and Oriental population, is likely to have produced a higher incidence and prevalence in Utah than would be seen in other areas of the United States.

Dermatitis herpetiformis in two American blacks: HLA type and clinical characteristics.

Dermatitis herpetiformis is a rare blistering skin disease characterized in part by granular IgA deposits at the dermoepidermal junction, an associated gluten-sensitive enteropathy, and a strong association with the human histocompatibility leukocyte antigen (HLA)-A1 (74% of patients with dermatitis herpetiformis), -B8 (88%), -DR3 (95%), and -DQw2 (100%). Dermatitis herpetiformis is rarely seen in American blacks and some investigators have postulated that this finding may be due to the decreased frequency of HLA-A1 and -B8 in American blacks compared with Caucasians (American blacks: HLA-A1 = 15.3%, HLA-B8 = 10.7%; Caucasian: HLA-A1 = 26.4%, HLA-B8 = 18.3%). This report describes two American blacks with dermatitis herpetiformis and reports the results of HLA typing of these subjects for HLA-A, -B, -C, -DR, and -DQ antigens. HLA typing revealed that neither patient expressed HLA-A1 or -B8; however, both patients did express the class II antigens most frequently seen in dermatitis herpetiformis, HLA-DR3 and -DQw2. Comparison of HLA class II antigen frequency in normal American blacks and Caucasians reveals a similar frequency of HLA-DR3 and -DQw2 (American blacks: HLA-DR3 = 27.6%, HLA-DQw2 = 40.9%; Caucasian: HLA-DR3 = 22.6%, HLA-DQw2 = 32.9%). These data confirm the importance of the HLA class II region in the pathogenesis of dermatitis herpetiformis. In addition, these data suggest that the rare occurrence of dermatitis herpetiformis in American blacks is not due to the decreased frequency of the HLA class I antigens -A1 and/or -B8 but rather is related to differences in the HLA class II region not detected by routine HLA typing.