Contact hypersensitivity to Indian standard patch test series correlates with disease severity among children with atopic dermatitis.

Background There is emerging evidence of a relationship between atopic dermatitis (AD) and allergic contact dermatitis (ACD), though the data available are scarce with conflicting viewpoints. We explored the occurrence of contact hypersensitivity among children with atopic dermatitis by patch testing them with the Indian standard series and tried to correlate the presence of contact hypersensitivity with the clinical severity of AD in these children. Methods In this single-centre, cross-sectional study, children between 6 months and 12 years diagnosed with atopic dermatitis were included and patch tested with the Indian standard series. Outcome parameters were the proportion of patients having positive patch-test reactions, the proportion of positive patch-test reactions for each allergen and factors associated with patch test positivity in atopic dermatitis. Results Of the 136 patients, 80 were boys. The mean age of the study population was 5.6 ± 3.2 years. Twenty-eight (20.6%) patients had patch test positivity at 96 h. Fragrance mix was the commonest allergen, followed by potassium dichromate, cobalt chloride hexahydrate and nickel. SCORing atopic dermatitis (SCORAD) was significantly higher in patients with positive patch tests as compared to patients with negative patch tests (P = 0.009). Conclusion Greater disease severity in atopic dermatitis was found to be associated with patch test positivity. Limitations Inability to establish relevance in about 50% of the patients was a limitation of our study. Follow-up data regarding the impact of allergen avoidance is not available.