This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Dermatitis, Subject name: Dental
Air-borne contact dermatitis can be diagnosed by- 
Select and explain. 
A. Skin biopsy, B. Patch test, C. Prick test, D. Estimation of serum IgE levels
B: Patch test
Answer: B: Patch test 
Explanation: air borne contact dermatitis is diagnosed by patch testing with the specific allergen. eg: pahenium is the common allergen tested using patch test. IADVL TEXTBOOK OF DERMATOLOGY, INDIAN PATCH TEST SERIES PAGE 581.