What role does IgG play in Haut?

The provided context contains no information about the role of IgG in the skin. Generally, IgG is an antibody involved in immune memory and defense. In the skin, IgG can be relevant in autoimmune blistering diseases like pemphigus vulgaris (where IgG attacks desmoglein) or in cutaneous lupus. It also plays a role in type II/III hypersensitivity reactions. However, consumer IgG food sensitivity tests are widely marketed for skin issues like acne or eczema, but the evidence for their clinical utility is weak. Most IgG against food reflects normal immune exposure, not pathology. Therefore, using such tests to guide diet for skin health is not evidence-based. A dermatologist should evaluate persistent skin problems, and if allergy is suspected, specific IgE testing is more appropriate. Evidence grade: unclear (no context provided).