Exposures and outcomes of children with urticaria seen in a pediatric practice-based research network: a case-control study.

Objectives: (1) To determine the duration, outcome, and associated findings of urticaria in children seen by general pediatricians; (2) to compare the exposure to foods, medications, insect stings or bites, and the presence of other symptoms in children with urticaria with controls; (3) to determine general pediatricians' management of urticaria.

Design: Case-control.

Participants: Children with urticaria seen by Utah Pediatric Practice Based Research Network members between August 1, 1999, and August 31, 2000. Control patients were matched for age and sex.

Main Outcome Measures: Duration of urticaria; associated symptoms; personal and family history of atopy; medications; ingestion of peanuts, nuts, shellfish, tomatoes, strawberries, or eggs; being stung by an insect; suspected cause, diagnostic studies; treatment.

Results: Fifty-two cases and 47 controls were enrolled. The mean duration of urticaria was 8.9 days (range, 1-50 days). Seventeen patients (33%) and 1 control patient were taking antibiotics (odds ratio [OR], 22.3; 95% confidence interval [CI], 2.8-176; chi(2), P<.001). Fourteen patients and 5 controls had gastrointestinal symptoms (OR, 3.1; 95% CI, 1.02-9.4; chi(2), P =.04). There were no differences between cases and controls for other symptoms, personal or family history of atopy, ingestion of the foods listed, insect sting, or other medications. A cause was suspected in 28 patients (54%): a "viral illness" (19%), antibiotics (15%), or a combination (35%).

Conclusions: Patients were more likely than controls to be taking an antibiotic and were more likely to have a personal or family history of atopy or to report ingesting foods commonly associated with urticaria. A viral illness was the most common cause suspected by pediatricians.