Atopic dermatitis associated with tropical endemic limbo-conjunctivitis: Epidemiology, clinical phenotypes, and allergological investigations

Background: Atopic dermatitis (AD) is on the increase worldwide. In Africa, 40% of cases are associated with tropical endemic limbo-conjunctivitis (TELC). Its predominance in early childhood has a major impact on the quality of life of children and their parents, leading to absenteeism from school and work. The aim of this study was to assess the particularities of AD associated with TELC in Dakar. Materials and Methods: This was a cross-sectional, multicenter study with prospective data collection over a six-month period, conducted at dermatology and ophthalmology departments in Dakar. All patients treated for atopic dermatitis with or without TELC were included in the study. Data entry and analysis were performed with SPSS 18. Results: From the study, 97 cases of atopic dermatitis were identified. Among these, 49 had AD associated with TELC. The sex ratio was 1.18 (36 boys and 13 girls). The mean age of patients was ten years. The age range between 5 and 10 years was more represented. There was atopy equivalent to allergic rhinitis in 44 cases, asthma in 16 cases, allergic conjunctivitis in 14 cases, and food allergy in 20 cases. 31 cases of AD were mild, 16 moderate, and 2 severe according to SCORAD. Patients were in stage I in 26 cases and in stage II in 13 cases according to Diallo’s TECL classification. All patients were managed by dermatologists and ophthalmologists. Aeroallergen prick tests were performed in thirty cases. Tests were positive for house dust mites in 23 cases (92%), animal dander in 11 cases (44%), molds in 7 cases (28%), and pollens in 2 cases (8%). Dermatophagoides pteronyssinus and farinae were the most common aeroallergens. Patch tests were positive for potassium dichromate in 4 cases, cobalt in 4 cases, nickel in 3 cases, and lanolin in 4 cases. Conclusion: AD associated with TECL remains common in tropical environments. They share common aggravating environmental factors, notably hypersensitivity to aeroallergens and a predominance in early childhood. The major impact on functional prognosis makes therapeutic education and multidisciplinary management of patients essential. Key words: Atopic dermatitis, Tropical limbo-conjunctivitis, Dakar