Evidence check: CYP2C19 in the context of Haut

CYP2C19 is a cytochrome P450 enzyme primarily expressed in the liver, responsible for metabolizing numerous drugs. In the context of skin („Haut“), there is no strong, direct evidence for a clinically relevant role of CYP2C19 variants. Although some dermatological agents – such as certain antifungals (e.g., voriconazole) or immunosuppressants – are partially metabolized by CYP2C19, genetic variability mainly affects systemic drug exposure rather than skin itself. Consumer DNA tests like MyBody-X can detect common CYP2C19 polymorphisms (*2, *3, *17) determining metabolizer status (poor, intermediate, normal, rapid). For skin conditions like acne, psoriasis, or eczema, no validated genotype–phenotype associations exist that would enable personalized topical therapy. Evidence is therefore rated as 'unclear': mechanistically plausible but lacking robust clinical data for skin indications. Caution is warranted: test results should never be used alone for drug dose adjustments; a physician consultation is essential.