Skin Prick Test and Patch Test: Environmental and Chemical Allergen Reactivity Pattern Among Yemeni Patients in Sana’a City, Yemen

Abdulbasit A Al-Ghoury,1,2 Jamil MAS Obaid,1,3 Waheed A Ali,4 Mohammed A Al-Shaybani5 1Laboratory Medicine Department, Faculty of Medicine and Health Sciences, Emirates International University, Sana’a, Yemen; 2Laboratory Medicine Department, Faculty of Medicine and Health Sciences, Amran University, Amran, Yemen; 3Medical Laboratory Sciences Department, Faculty of Medicine and Health Sciences, Ibb University, Ibb, Yemen; 4Department of Microbiology and Immunology, Faculty of Medicine and Health Sciences, Taiz University, Taiz, Yemen; 5Elaj Medical Center, Sana’a, YemenCorrespondence: Jamil MAS Obaid, Department of Medical Laboratory Sciences, Ibb University, B.O.Box: 70270, Asalaba, Ibb City, Yemen, Tel +00967773979848, Email [email protected]; [email protected]: The prevalence of hypersensitivity reactions to different allergens varies according to the population studied and is subject to environmental and lifestyle factors. Early and delayed hypersensitivity are diagnosed with skin prick test and patch test.Objective: This study aimed to identify the common environmental and chemical allergens sensitizing Yemeni allergic patients.Subjects and Methods: A retrospective study was conducted using registries of patients who attended Elaj Medical Center in Sana’a city, Yemen, from January 1st to December 31st 2023. The collected data included sex, age, and the clinical laboratory test results of the skin prick test and the patch test.Results: The skin prick test was performed on sixty-five patients compared to twenty-two who were tested with a patch test. Most of the positive participants were male, aged between 18 and 40 years. The most frequent environmental allergens causing immediate hypersensitivity were Dermatophagoides farinae and Dermatophagoides pteronyssinus mites (64.6% and 69.2%, respectively), Aspergillus (47.7%), cat dander and dog dander (43.1% and 35.4%, respectively). Dermatophagoides farinae mites mostly sensitized females with an odds ratio of 3.43 (95% CI, 1.13– 10.42, p=0.05). The most common chemical allergens that caused delayed hypersensitization were paraphenylenediamine (45.5%), potassium bichromate (45.5%), cobalt sulfate (36.4%), thiuram mix (27.3%), Vaseline (27.3%), and nickel sulfate (27.3%). Polysensitization was more frequent. The age of patients was directly proportional to the number of allergens responsible for immediate hypersensitivity (r-0.298, p=0.016).Conclusion: Yemeni patients exhibited high sensitization to aeroallergens and chemical allergens. Females showed a higher propensity for polysensitization. The pattern of sensitization to environmental and chemical allergens in Yemen differs somewhat from neighboring Arab and Asian countries. Further multi-center studies are needed to support and establish a standard country-specific allergens panel for testing.Keywords: skin prick test, patch test, allergens, atopy, immediate hypersensitivity, delayed hypersensitivity, Yemen