"Parthenium dermatitis: an unsuspected allergy".

Congress grass (Parthenium hysterophorus) is a common weed growing wild in the urban and semiurban environs of North India. Cases of eczematous dermatitis caused by it generally escape clinical detection and are consequently wrongly diagnosed. An interesting case of Parthenium dermatitis treated with a high-dose course of desensitisation is presented to underscore the probability of the entity in obscure cases of contact dermatitis and eczema.