Scoping review: biomarkers in chronic inducible urticaria.

Objective: Chronic inducible urticaria (CIndU) affects approximately 0.5% of the population and is characterized by wheals triggered by specific stimuli, such as cold or heat exposure, physical exertion, mechanical friction, vibration, or delayed pressure, distinguishing it from chronic spontaneous urticaria. Biomarkers may improve diagnosis, define endotypes, predict disease course, monitor treatment responses, and subsequently guide personalized treatment strategies. This scoping review aimed to map current evidence on diagnostic, prognostic, predictive, and monitoring or treatment-response biomarkers in CIndU, with a focus on H1-antihistamine and omalizumab therapy. Methods: This scoping review was conducted according to the Joanna Briggs Institute methodology and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping reviews guidelines. Embase, MEDLINE, and Web of Science were searched from inception to January 29, 2026. Screening and data extraction were performed independently by two reviewers. Results: Out of 3394 screened studies, 42 studies were included, revealing a heterogeneous and exploratory evidence base with limited validation across biomarkers and CIndU subtypes. No diagnostic biomarkers were identified for several subtypes, including cold, delayed pressure, and solar urticaria. In cholinergic urticaria, sweat-related immunoglobulin E (IgE) showed moderate diagnostic potential for a sweat allergy endotype but requires validation. In symptomatic dermographism, exploratory omics-based approaches identified molecular alterations but lack clinical applicability. Across CIndU subtypes, prognostic biomarkers showed exploratory associations with disease duration and severity. In cold urticaria, provocation-based parameters were associated with disease severity and response to H1-antihistamines, while total IgE showed exploratory potential for predicting omalizumab response. Routine laboratory markers were generally not reliable for treatment response or disease monitoring in CIndU. Conclusion: Several promising exploratory biomarkers have been identified across CIndU subtypes, providing a foundation for future research. Integrative multi-omics approaches, such as those being applied in the SKINERGY CIndU pilot study within the Next Generation ImmunoDermatology consortium, hold promise for advancing biomarker discovery. External validation in large, well-characterized cohorts through international networks, such as Urticaria Centers of Reference and Excellence (UCARE), will be pivotal for clinical translation.