Allergic contact dermatitis;guinea pig sensitization;cosmetic products;cross-sensitization
2 protocols are presented to predict and assess reactions after application of chemicals or cosmetic products, either raw materials or finished products. The first is an open epidermal induction and challenge, the intensity of the reaction being maximized by injecting Freund's complete adjuvant into the toot pad. The second allows detection of weaker allergens and is a quasi-intradermal induction: both the adjuvant and test substance are injected into the foot pad. In both protocols, the challenge consisted of a single topical application in the lumbar region of 10 μl of test substance and components, allowing study of Cross-sensitization, the large surface available permitting 6 different contacts.