patch testing
A diagnostic procedure to identify contact allergens by applying potential irritants to the skin under occlusive patches.
Full Definition
Patch testing is the gold standard for diagnosing allergic contact dermatitis in pediatric patients. The procedure involves applying standardized allergens to the patient's back using adhesive patches, which remain in place for 48 hours. Readings are performed at 72 and 96 hours (sometimes extending to one week) to assess for delayed-type hypersensitivity reactions. In children, modified protocols may be used with age-appropriate allergen panels and shorter application times. Common pediatric allergens include nickel, fragrance mix, preservatives, and topical medications. Results guide avoidance strategies and treatment planning.
Usage
Usage note: Specify reading times and reaction grading scale when documenting results.
In Context
- "Patch testing revealed strong positive reactions to nickel and fragrance mix at 96 hours." — Allergy test results
- "Patient scheduled for patch testing to evaluate recurrent facial dermatitis of unknown etiology." — Consultation plan