Parthenium dermatitis: is it a systemic contact dermatitis or an airborne contact dermatitis?

摘要

We describe here a Parthenium hysterophorus patch-test-positive patient with widespread dermatitis of non-airborne contact dermatitis pattern, improving while staying in Shimla (a parthenium-free area) and rapidly worsening while visiting his native place, where there was exuberant parthenium growth. After recovery, inhalation of fresh plant material from a polythene bag resulted in exacerbation of dermatitis and pruritus within 8-10 hr, without any respiratory symptoms. The possible pathomechanism of such a phenomenon is discussed.