A 45 years old male presents with itchy papules over face, neck and V area of chest for the last three years, which are exacerbated in summers and improved in winters. What test will you do to confirm diagnosis?

Ans: A. Patch test(Ref: Rooks 8/e p26.93, Fitzpatrick 6/e p1451, 1309)The clinical picture mentioned above is suggestive of air-borne contact dermatitis, which is a type of allergic contact dermatitis.Most common source is Pahenium exposure and it leads to dermatitis involving the exposed pas, i.e. Face, upper neck, cubital and popliteal fossa.The only useful and reliable methodfir the diagnosis of allergic contact dermatitis remains the patch test.