ANALYSIS OF PATCH TESTING IN ATOPIC PATIENTS

Background- Atopic Dermatitis is a major problem which can be aggravated by various allergens. There is a dispute as to whether these patients are at a risk of developing allergic contact dermatitis as they are less prone to develop Type-IV Reactions. Since atopic dermatitis can be triggered by various allergens we analysed the patch test results of patients who presented with atopic dermatitis (AD). Aim - To evaluate the role of patch testing and to obtain valuable information of contact sensitivity in atopics. Method- Fifty atopics diagnosed according to Hanifin Rajkas Criteria who were not on medications and without active disease were patch tested with Indian Standard Series (ISS) and results interpreted according to International Contact Dermatitis Research Group (ICDRG). The results of patch test were analyzed to determine the most common allergen. Patients diagnosed as atopic dermatitis according to Hanifin Rajkas Criteria were included in the study and patients who were on immunosuppressive drugs, corticosteroids, pregnancy, lactation and with extensive dermatitis were excluded from the study.On analysis of patch testing in 50 patients with atopic dermatitis, 42 of patients showed positive reaction with patch test antigens. Out of that 33 of patients showed positivity to fragrance mix, 24 to paraphenylenediamine (PPD), 19 to cobalt chloride, 19 to potassium dichromate, 14.3 to balsam of Peru, 14.3 to nickel sulfate, 9.5 to neomycin sulfate, 9.5 chlorocresol and 5 each to gentamycin, colophony, wool, alcohol, black rubber mix, para-tertiary butyl phenol formaldehyde resin (P-T BPF Resin) and paraben, (Table 2). Out of 42 of positive patients, 52.3 of them showed multiple positivities. The results of multiple positivities revealed varying combinations out of which potassium dichromate with cobalt and paraphenylenediamine (PPD) with balsam of Peru were the commonest (Table 2). Conclusion-Patients with atopic dermatitis should be patch tested when indicated and our study indicates that it adds valuable information about contact sensitivity in these patients.