36 year old farmer presented to dermatology depament with pruritic erythematous lesions on arms, forearms, face and retroauricular area after removal of weeds in his farm. A diagnosis of phytodermatitis was made. What is the most likely plant responsible for this condition?

Pahenium hysterophorus or congress weed is the most common plant producing phytodermatitis in india. It preseents with pruritic skin lesions on exposed areas even involving the photoprotected ares. Hence called pseudophotodermatitis. Allergen responsible is sesquiterpene lactone. Ref: Rook textbook of dermatology, 8th edition, Page 26.75