Deposition of granular IgA relative to clinical lesions in dermatitis herpetiformis

Quality of Life and Gastrointestinal Symptoms in Long-Term Treated Dermatitis Herpetiformis Patients: A Cross-Sectional Study in Finland

“…Out of these 569, 78 patients had been diagnosed with DH, and they were enrolled as cases in the study group. The medical records of the DH patients were reviewed to verify that all had had skin symptoms compatible with DH at the time of diagnosis, and that the presence of skin IgA deposits in the papillary dermis was confirmed by direct immunofluorescence [3].…”

“…DH manifests as an itchy, blistering rash predominantly on the extensor surfaces of elbows and knees, and on the buttocks and scalp [2]. The diagnosis of DH is based on typical clinical manifestation and the demonstration of granular immunoglobulin A (IgA) deposits in the papillary dermis [3]. The majority of DH patients evince small-bowel mucosal villous atrophy characteristic of celiac disease, and the remainder have celiac-type inflammation in the gut.…”

Dermatitis herpetiformis

“…Granular deposits of IgA at the tips of dermal papillae are pathognomonic for DH (in contrast to the linear pattern of IgA deposition seen in LABD; Fig 2, B). [1][2][3][4] The IgA deposits in DH are thought to be polyclonal but are mainly composed of IgA1. 5 Occasionally, granular deposits along the basement membrane zone occur in DH, which can lead to misdiagnosis as LABD.…”

“…1 Interestingly, these deposits are not altered by pharmacologic therapy for DH, but do slowly resolve on a gluten-free diet (GFD). 2,3 The site of biopsy for direct immunofluorescence is of vital importance.…”

“…3 In fact, biopsy specimens of lesional skin often yield false-negative results on direct immunofluorescence. 3,6 Serologic testing is a useful adjunct to tissue-based studies. A number of serologic markers are shared between DH and CD, as might be expected given their close relationship.…”