D2.53 - Impact of Smoking on the Clinical and Allergological Profile of Allergic Contact Dermatitis: An 8-Year Analytical Study

Clinical and epidemiological studies have suggested a potential link between tobacco exposure and allergic risk. This research aims to investigate the effect of smoking on the clinical presentation and epidemiological profile of Allergic Contact Dermatitis (ACD), as well as the impact of smoking on the allergological profile of eczema.

A retrospective descriptive and analytical study was conducted over an 8-year period, including all patients followed for ACD at Farhat Hached Hospital in Sousse. We compared two groups: Group 1 (smokers with ACD) and Group 2 (non-smokers with ACD).

A total of 767 patients were included, 40% of whom were smokers. The smoking group was characterized by a male predominance (72.6% vs. 24.3%; p < 0.001), a lower prevalence of personal atopy (p = 0.002) and family atopy (p = 10^-3), a higher frequency of active employment (89.2% vs. 81.7%; p < 0.001), and longer occupational seniority (13.3 years vs. 11 years; p = 0.01). Among the allergens in the European Baseline Series (EBS), positive patch tests for chromium and cobalt were more frequently observed in smokers (p = 10^-3). A predominance of ACD due to preservatives was found among smokers, notably for Balsam of Peru (p = 0.001), Rosin (p = 0.001), Formaldehyde (p = 10^-3), and Kathon CG (p = 0.042). Following linear logistic regression, the variables independently associated with the smoking population were male gender (OR = 12.12; 95% CI [6.07 - 24.21]) and allergy to Kathon CG (OR = 3.69; 95% CI [1.24 - 10.81]).

This study reveals a different  clinical and allergological phenotype among  smokers with Allergic Contact Dermatitis (ACD), characterized by a male predominance and a particular sensitization profile. Smoking may be a powerful cofactor in skin sensitisation due to the strong correlation with metals and preservatives, especially the almost four-fold increased risk of Kathon CG sensitisation. These results highlight the necessity of systematic smoking status screening for ACD patients as well as more investigation into the combined impact of occupational allergens and tobacco smoke on the skin barrier