Changing allergen pattern in allergic contact dermatitis

Abstract

Background: Allergic contact dermatitis (ACD), a T-cell mediated type 4 hypersensitivity reaction, occurs when skin get exposed to exogenous allergens. True incidence of ACD is difficult to estimate. Common sensitizers also vary with place, patient profile and time. With increasing complexity of human life, our skin gets exposed to a large spectrum of chemical and biological products, thereby increasing allergic sensitisation. Aim and objectives: To identify the common allergens causing allergic contact dermatitis in a tertiary health centre and to determine the clinical profile of patients presenting with the same. Settings and Design: A cross sectional study was conducted in a tertiary health centre in Tumkur. Materials and methods: Fifty patients with suspected allergic contact dermatitis were enrolled. Demographic data, clinical history, examination and patch testing with Indian standard series containing 19 allergens was done after subsidence of active eczema. Statistical analysis used: Descriptive statistics were reported using mean and standard deviation for continuous variables, number and percentage for categorical variables. The Chi-Square test was used and a 'p' value of 0.05 proportion or less was considered statistically significant. Results: Out of the 50, 35 were patch test positive. There was a slight male predominance(4:3) and majority belonged to the age group 31-50 years. The common allergens in decreasing frequency were parthenium, fragrance mix, PPD, potassium dichromate and chlorocresol. Conclusions: With changing lifestyle and urbanization, the allergens keep on varying. The clinical pattern also varies with the causative allergen/s. Such studies help to detect the common prevalent allergens in a locality and thereby avoid misdiagnosis and also in creating awareness.