AP BIOLOGY

Detailed explanation-1: -It is caused by airborne dry and friable plant particles including trichomes, and the most important allergens responsible for allergic contact dermatitis are sesquiterpene lactones. The combined type IV and type I hypersensitivity to parthenium has been recently postulated.

Detailed explanation-2: -Parthenium allergy is caused by direct and indirect contact with Parthenium hysterophorus L. of the Compositae family, accidentally introduced into India from the USA 20 years ago. Its distribution was supported by the optimal environmental conditions of this country.

Detailed explanation-3: -Parthenium or carrot grass has become ubiquitous and causes pollen allergy. Parthenium came into India as a contaminant with imported.

Detailed explanation-4: -Parthenium dermatitis is caused by dry powder of leaves and flowers and hair-like structures (trichomes). Sesquiterpene lactones (SQLs) are the most important allergens responsible for ACD to parthenium.

Detailed explanation-5: -The plant produces allelopathic chemicals that suppress crop and pasture plants, and allergens that affect humans and livestock. It also frequently causes pollen allergies.