Methods: Prospective study performed in the Allergy and Immunology Department between May 2012 and June 2013, including adult (19-59 years) and elderly patients (> 60 years) with suspicion of ACD. For SPT, we used the Brazilian standard battery composed of 30 substances and a cosmetic battery with 15 components both standardized by Brazilian Study Group of Contact Dermatitis. The tests were applied using FINN Chambers containers and the interpretation was according to the International Contact Dermatitis Research Group recommendations. Data were analysed by the parametric method ANOVA (analysis of variance).
Results: We included 211 patients, 72 elderly and 139 adults. Of the 72 elderly, 57 were female (79%) and 107 (77%) had the same gender among all adults. Among the elderly, 46 (63.9%) of tests were positive (p = 0.66). There was no statistical significance regarding the topography of eczema among groups. The upper and lower limbs were the most affected regions in elderly while hands were most important in adults. We showed a higher sensitization in the elderly group of the following substances: Nickel sulphate (22.2%) paraphenylenediamine (15.3%), butyl phenol para tertiary (13.9%) and nitrofurazone (13.9%). Meanwhile, the most significant substances among the adults were: quaternium 15 (p = 0.010), nitrofurazone (p = 0.013), mercapto mix (p = 0.031), and neomycin (p = 0.048).
Conclusions: Based on the positivity in both adults and elderly patients, we demonstrated that the skin patch test is an important diagnostic tool in ACD regardeless to the age. In the elderly subjects, the sensitizer substances are frequently used in topical drugs, mainly antimicrobial, are important etiologic agents. The nickel sulfate remains a major sensitizer in both groups.