◼ The scratch test introduces a minute allergen into the epidermis, producing an immediate wheal-and-flare reaction if IgE-mediated sensitivity exists
◼ The intradermal test delivers allergens into the dermis, offering greater sensitivity, and is used when scratch tests are negative but suspicion is high
◼ The patch test identifies Type IV delayed hypersensitivity, with allergens applied on the skin for 48–72 hours, useful in contact dermatitis evaluation
◼ Combining these tests ensures detection of both immediate and delayed allergic responses, giving a more complete allergy profile
◼ Accurate diagnosis helps in allergen avoidance, targeted immunotherapy, and better long-term symptom control