Evidence check: HLA-DQ2 in the context of Haut

HLA-DQ2 is a well-established genetic risk factor for celiac disease, which can present with skin manifestations such as dermatitis herpetiformis (an intensely itchy, blistering rash). The evidence linking HLA-DQ2 to this skin condition is strong (human-strong). However, a positive genetic test does not diagnose celiac disease or skin disease: only about 3 % of carriers develop celiac, and not all celiac patients have skin involvement. Therefore, the test serves as a risk assessment, not a diagnostic tool. For skin issues like chronic itching or blisters, follow-up with serology (anti-tTG antibodies) and possibly a skin biopsy is necessary. IgG-based food sensitivity panels, as promoted in some combo tests, lack scientific validity for this purpose and may lead to unnecessary dietary restrictions. In summary, HLA-DQ2 testing in the context of skin provides a useful clue but requires medical interpretation. The evidence for the association is robust, but the standalone genetic test has limited clinical utility.