Contact sensitization of older patients in an academic department in Naples

BACKGROUND: Contact allergy develops in predisposed individuals as a consequence of environmental exposure to allergens. Exposure patterns change over time because of many factors (sex, age, occupation, fashion trends, official regulations), and the delayed hypersensitivity response depends significantly on the age of the subject. OBJECTIVE: The aim of the present study was to investigate the prevalence of contact sensitization in older patients (older than 65 years) referred to our allergologic clinic. METHODS: All patients were patch-tested with the standard series of the Societè Italiana di Dermatologia Allergologica, Professionale e Ambientale, and 32 patients were also tested with additional series. RESULTS: Of 117 examined subjects, 48 (41%) developed at least one positive reaction whereas 22 of 117 (19%) showed more than one sensitization. Allergic contact dermatitis was detected in 13% of our sample. The five most frequent allergens were nickel sulfate (13.7%), potassium dichromate (11.1%), cobalt chloride (7.7%), para-phenylenediamine (5.2%), and balsam of Peru (4.3%). CONCLUSION: These findings suggest an age-dependent decline of overall positive patch-test reactions but a higher sensitization rate to some allergens.