Eating increases disease activity in pediatric patients with symptomatic dermographism.

Background: Symptomatic dermographism (SD) is the most common form of chronic inducible urticaria. SD disease activity increases with food intake in adult patients. Whether this is also so in children with SD is currently unknown. Objective: To assess children with SD for their disease activity by standardized provocation testing before and after eating. Methods: We subjected 44 children with SD (29 girls; median [interquartile range] age 12.5 years [8.3-15 years]), before and after eating, to standardized skin provocation testing with a dermographometer. Dermographometer scores were calculated based on responses evaluated at 1-minute intervals for 10 minutes and recorded as negative (-) or positive (+ to ++++). Clinical characteristics and urticaria control test scores were documented. Results: Dermographometer scores before eating were 2.3 of 4 on average and inversely correlated with urticaria control test scores. Dermographometer scores were higher after eating than before eating. Of 44 children with SD, 35 had increased dermographometer scores after eating and 9 patients had a postprandial increase of ≥1 point. Eating-induced increases in dermographometer scores were linked to earlier whealing in 17 of 35 patients, and differences in preprandial versus postprandial dermographometer responses were more pronounced at earlier than later time points after testing. Conclusion: Disease activity, as assessed by provocation testing, is increased in most pediatric patients with SD after eating. Future studies should explore the prevalence of food-exacerbated SD in larger pediatric SD populations. Most pediatric patients with symptomatic dermographism have higher disease activity, assessed by provocation testing, after eating as compared to before eating. Standardized provocation testing and trigger threshold assessments in children with symptomatic dermographism should be performed before and after eating. Knowledge of food-exacerbated disease may help patients with the management of their symptomatic dermographism.