Abstract Background Drug hypersensitivity (DHS) is a neglected area of research in pediatric chronic spontaneous urticaria (CSU). Studies using diagnostic tests are exceedingly scarce and the true prevalence and clinical profile remain unclear. This study aimed to investigate DHS in pediatric CSU through diagnostic testing and evaluation of associated clinical and laboratory features. Methods This nested case–control study was conducted at a tertiary referral center and included 250 children with CSU followed between January 2018 and December 2023. Based on a structured clinical assessment guided by the ENDA/GA 2 LEN framework, 28 children (11.2%; 95% CI: 7.9%–15.7%) were identified as having suspected DHS. All underwent further diagnostic evaluation, including skin testing and drug provocation tests. Demographic, clinical, and laboratory data were recorded. These data were compared among children with confirmed DHS, those in whom DHS was excluded after diagnostic workup, and an age‐ and sex‐matched control group of 48 CSU children without a history of DHS. Results Among the children with suspected DHS, 14 (50%) were confirmed by diagnostic evaluation, corresponding to an overall prevalence of 5.6% (95% CI: 3.4%–9.2%). Among confirmed cases, β‐lactams were the leading agents (58.3%), followed by NSAIDs/paracetamol (33.3%). Selective hypersensitivity was identified in 7 patients to antibiotics (2.8%) and in 4 to NSAIDs/paracetamol (1.6%), while 3 (1.2%) had multiple DHS. Conclusion Drug hypersensitivity is common in children with CSU. Clinical history is informative and a suggestive drug‐related history should guide targeted diagnostic testing.
Gürbüz et al. (Fri,) studied this question.