Oral hyposensitization in patients with contact dermatitis from Parthenium hysterophorus.

Parthenium hysterophorus is the commonest cause of airborne contact dermatitis in northern India. Treatment is mostly palliative and consists of repeated courses of antihistamines and topical and/or systemic corticosteroids. We have evaluated the effect of oral hyposensitization as an alternative therapeutic modality. In 70% of those patients who completed the study, there was a gradual improvement in their clinical status, as evident from a fall in their clinical severity score for eczema. 30% of patients had an exacerbation during the course of the study and hence hyposensitization in them was stopped. Patients tolerated therapy well and no significant side-effects were seen, except for abdominal pain, 'heartburn' and cheilitis.