oa A review of patch-test data over the period of eight years in the allergy and immunology department in Qatar

Background: Patch testing is the primary diagnostic approach for contact dermatitis,¹ an inflammatory skin reaction caused by exposure to external irritants. The pathophysiology of contact dermatitis may entail an immunological response (hypersensitivity type IV), a non-immunological response (irritant contact dermatitis), or a mix of the two. The diagnosis of contact dermatitis requires a correlation between a positive patch test and clinical relevance.² This study aims to determine the prevalence of allergy sensitization among adults in Qatar and the allergens most frequently associated with positive patch test findings.

Methods: Retrospective analysis used patch testing data from 2015 to 2022.

Results: Of the 87 patients tested, 43 had at least one positive reaction (mean age 41.7; range 19–68). Females were 33 of the total patients (76.7%). Thirteen (30%) patients had two or more positive reactions. The most common allergen groups associated with positive patch test reactions were nickel sulfate no. 12 (27.9%), and all reactants were female. followed by gold sodium thiosulfate no. 10 (23.3%, F:M = 2.3), p-phenylenediamine no. 10 (23.3%, F:M = 1.5), and p-tert-butylphenol formaldehyde resin no. 7 (16.2%, F:M = 6). Twenty-six reactants had one or more allergic disorders (allergic rhinitis, asthma, drug allergy, insect bite allergy, or chronic idiopathic urticaria), and 11 had atopic dermatitis.

Conclusion: Triggering agents for contact dermatitis vary among geographic regions and populations. This study gives an idea of the allergens that are the most common sensitizers among the contact dermatitis population in the adult allergy clinic in Qatar.