Allergic Contact Dermatitis Due To Parthenium Hysterophorus.

Fifty cases of allergic contact dermatitis from Parthenium hysterophorus have been studied in detail. Clinico-epidemiological features have been described. Patients present with any of the four observed patterns of dermatitis viz. atopic, photosensitivity, seborrhoeic and miscellaneous. Patients were patch tested with 12 extracts of the plants in six solvents producing differing reaction. Limited chemical analysis of the plant extracts yielded various fractions of which three were found to be immunologically active. Chemical nature of parthenin which is a known allergen of this plant has been studied. Possibility of cross sensitivity with other plants is briefed.