Failure of titer of contact hypersensitivity to correlate with clinical severity and therapeutic response in contact dermatitis caused by parthenium.

ABSTRACT

BACKGROUND: The titer of contact hypersensitivity (TCH) has been used to determine the degree of contact hypersensitivity in patients with contact dermatitis. The values have been found to vary in different individuals and also in the same individual at different times apparently due to the varying severity of the disease. We evaluated the correlation of TCH with disease severity and therapeutic response in patients of contact dermatitis caused by the plant Parthenium hysterophorus. METHODS: Forty-two patients, 30 (71.4%) males and 12 (28.6%) females, aged between 30-75 years, having air-borne contact dermatitis to Parthenium hysterophorus for 0.5-20 years were included in the study. The disease severity and TCH at baseline were recorded in all the patients. They were treated with azathioprine and followed up every month for 4-69 months. The TCH was repeated every 3 months and the last recorded TCH value was taken for analysis in each patient. RESULTS: The baseline clinical severity score (CSS) varied from 10-80 (mean +/- SD 35.47 +/- 19.41) in these patients. It ranged from 10-30 in 22 (52.4%) patients, from 31-50 in 14 (33.3%) patients, and was more than 50 in 6 (14.3%) patients. The baseline TCH to Parthenium was undiluted (UD) in 2 (4.8%), 110 in 15 (35.7%), 1100 in 20 (47.6%), and 11000 in 5 (11.9%) patients respectively. At the end of the study, the clinical severity of the disease decreased in most of the patients. The CSS came down to 0 in 31 patients, to 10-20, and to 50 in 4 patients each, but remained stable in three patients who had baseline CSS from 20-40. The overall mean CSS came down from 35.47 +/- 19.41 to 4.76 +/- 9.43 (p = 0.002). However, there was no significant change in the TCH levels over time (p = 0.153). The last TCH value was negative in 2 (4.8%) patients, undiluted in 5 (11.9%), 110 in 10 (23.8%), 1100 in 18 (42.9%), and 11000 in 7 (16.7%) patients. There was no change in the TCH values in 16 (38.1%) patients while it increased or decreased by 1-2 dilutions in 12 (28.6%) patients each. CONCLUSIONS: We therefore conclude that the TCH does not correlate with the clinical severity of contact dermatitis or response to treatment.