irritant vs allergic

Resolves after 12 hours of discontinuing the offending substance

● 36 to 48 hours to manifest symptoms and persists for several days (after removal of allergen)

● Cell-mediated delayed-type (type IV) hypersensitivity reaction

Excessive cleansing (with the additional use of feminine wash) of the vulvar skin and urinary or fecal incontinence (common in babies and old age in diapers), cosmetic or therapeutic agents including vaginal contraceptives, lubricants, perfumes (common misconception*), douches, fabric dyes, fabric softeners, synthetic fibers, bleaches, soaps, chlorine dyes in toilet fissures and local anesthetic creams

Development of antigen specific T-cells may return to the skin at the next contact with allergen

is among the most common allergen