CLINICALLY RELEVANT ALLERGENS AND SOCIODEMOGRAPHIC CHARACTERISTICS IN PATIENTS WITH ALLERGIC CONTACT CHEILITIS, A CROSS-SECTIONAL STUDY

Abstract

Background: Allergic contact cheilitis (ACC) is a subtype of allergic contact dermatitis affecting the lips, often caused by allergens in daily-use products. Accurate diagnosis through patch testing is essential for effective management. Objective: To identify common allergens and their clinical relevance in patients with ACC and assess the impact of allergen avoidance on quality of life. Methods: This prospective study included patients with cheilitis who referred for patch testing between January 2024 and December 2024 at the Srinakharinwirot (SWU) Skin Center, Bangkok, Thailand. They were all patch tested with the SWU Baseline Series, our dental and cheilitis series, our preservative and vehicle series, and patient’s personal products. Patch test readings were performed on Days 2, 3, and 7. A diagnosis of ACC was established based on the clinical presentation of an eczematous lip lesions and at least one relevant positive patch test result. Follow-up evaluations were performed on Days 14 and 49 to assess clinical improvement, patients’ quality of life using the Dermatology Life Quality Index (DLQI), and adverse events (i.e., erythema, dyspigmentation, flaring of dermatitis, and pruritus). Results: A total of 80 patients were included with 78 patients diagnosed with ACC. The majority were female (92.30%), with a mean age of 30.11 years. The average symptom duration was 20.27 months, with 83.34% experienced symptoms lasting over three months. Allergic rhinitis was the most frequent comorbidity. The most frequent clinically relevant allergens were hydroperoxides of linalool (SPIN 5585.64.62), gallate mix (SPIN 2096.67), sodium benzoate (SPIN 1665.64), propylene glycol (SPIN 1601.03), and Myroxylon pereirae (SPIN 1270.77). Common sources were lip products and toothpaste. Personal product testing showed 14.92% positives (lip products 8.64%, toothpaste 4.18%). Mean DLQI significantly improved from 10.10 at baseline to 2.42 by Day 49 following allergen avoidance. Patch testing was well tolerated, with only transient erythema and mild post-inflammatory hyperpigmentation. Dermatitis flare-ups were infrequent and resolved with allergen avoidance or minimal intervention. Pruritus peaked in the early post-test period and near resolved by Day 49. Conclusion: Gallate mix, hydroperoxides of linalool, and sodium benzoate are top three allergens in ACC. Allergen avoidance significantly improves patients’ quality of life. highlighting the importance of individualized allergen identification in ACC management.-