The review, written by Shuayb Elkhalifa and Mohamed Abuzakouk of Cleveland Clinic Abu Dhabi and the University of Manchester, takes stock of every scoring system and biomarker currently available in urticaria and angioedema, and asks a blunt question: can any of them identify, at the first specialist visit, which patients are headed for a difficult course? Their answer, distilled from a structured search of PubMed, Embase, and recent international guidelines, is a careful no. The tools clinicians use every day measure the present; the biomarkers described in the literature hint at the future; and nothing yet combines the two into a validated instrument that can be used at the bedside.

The distinction matters because the 2026 update of the international urticaria guideline has dramatically expanded the therapeutic arsenal. Treatment still begins with a second-generation H1 antihistamine, escalated to a fourfold dose, but the advanced options now include omalizumab, the anti-IgE antibody that transformed care of antihistamine-refractory disease; dupilumab, which blocks interleukin 4 and interleukin 13 signaling; and remibrutinib, an oral Bruton tyrosine kinase inhibitor that works downstream of the IgE receptor on mast cells and basophils. Ciclosporin remains a later-line immunosuppressive alternative. Yet the stepwise algorithm is organized entirely around treatment response. A substantial proportion of patients remain inadequately controlled despite guideline-directed antihistamine therapy, and difficult-to-control disease is typically recognized only after months of sequential escalation, during which patients accumulate symptoms, corticosteroid exposure, and healthcare costs.

The validated instruments in routine use are exemplary at what they do, which the review argues is precisely the problem. The Urticaria Activity Score over seven days, known as UAS7, sums a daily diary of wheal number and itch intensity into a score from 0 to 42, with bands marking mild, moderate, and severe activity. The four-item Urticaria Control Test captures control over recent weeks, with a score of 12 or more indicating well-controlled disease, and the 23-item Chronic Urticaria Quality of Life Questionnaire measures the disease’s toll on daily life, a burden the authors note is comparable to that of ischaemic heart disease. Parallel instruments exist for angioedema: the Angioedema Activity Score, the Angioedema Quality of Life Questionnaire, and the Angioedema Control Test. All of these were designed to quantify the current state of disease and to be responsive to change over time. None was built with longitudinal outcome modelling, none incorporates immunological variables, and none can distinguish a patient with transient severe disease from one facing persistent, treatment-refractory illness.

The biomarker literature tells a more mechanistically interesting story, centered on what researchers call the type IIb autoimmune endotype. In roughly 40 percent of patients, the inflammation is driven by autoantibodies: either IgE autoantibodies against self-antigens in type I autoallergic disease, or IgG autoantibodies that directly activate mast cells in type IIb disease, with many patients showing features of both. In research settings this endotype is confirmed by a positive autologous serum skin test or basophil activation test, but in routine practice it can be approximated by a cluster of cheap, accessible findings: a low total IgE, elevated IgG anti-thyroid peroxidase antibodies, basopenia, and eosinopenia. The updated guideline now recommends that specialist patients have total IgE, anti-thyroid peroxidase, a differential blood count, and C-reactive protein measured, and it singles out the ratio of IgG anti-thyroid peroxidase to total IgE as the best current surrogate for the type IIb endotype.

These markers carry prognostic weight because they track with treatment response. A low baseline total IgE is associated with coexisting autoimmune disease and a slower, only partial response to omalizumab. In the original study by Bras and colleagues, a ratio of IgG anti-thyroid peroxidase to total IgE above 0.154 was associated with roughly tenfold higher odds of a poor omalizumab response, although the review stresses that cutoffs for the individual markers vary between studies, with low-IgE thresholds ranging from about 40 to 44 IU/mL, and that the optimal ratio value requires prospective confirmation. Raised C-reactive protein, raised D-dimer, and reduced basophil and eosinophil counts have been linked with more active disease and slower response. Exploratory machine learning work has even used baseline D-dimer and C-reactive protein to classify patients as early, late, or non-responders to omalizumab. But the authors draw a firm line: nearly all of this evidence is associative, few markers have undergone prospective validation, and none constitutes a validated predictor of treatment failure.

A conceptual muddle runs through the field, and untangling it is one of the review’s central contributions. Monitoring tools answer how active or controlled disease is right now. Prognostic markers answer who is likely to have persistent or difficult-to-control disease, a category that includes long disease duration, high baseline activity, angioedema, coexisting chronic inducible urticaria, and the autoimmune phenotype. Predictive biomarkers answer who is likely to respond to a specific therapy. These are different questions targeting different outcomes, since disease persistence, disease severity, and poor treatment response are related but distinct. Thyroid autoimmunity emerges as the most consistent comorbid signal, associated with longer disease duration, greater severity, and lower response rates at 24 weeks of treatment. Prognostic information, the review concludes, is scattered across separate variables and separate studies, never assembled into a validated instrument.

The newest drugs complicate the picture further. Dupilumab is effective irrespective of baseline IgE, and its benefit may be greatest in patients with a type 2 inflammatory profile or atopic comorbidity, but no validated response predictors exist. Remibrutinib, acting downstream of the high-affinity IgE receptor, appears effective across endotypes, including in patients who have failed anti-IgE therapy, and works independently of both baseline IgE and previous omalizumab use. Direct comparisons of the three advanced agents are only beginning to appear. The implication is that biomarkers predictive for omalizumab may be uninformative for dupilumab or remibrutinib, and future prediction models will probably need to be developed and validated separately for each mechanism of action.

The review’s most concrete proposal is the CLARITY framework, presented explicitly as an investigational example rather than a validated clinical instrument. It assigns one point to each of seven domains spelled out by its letters: comorbid autoimmune disease, low total IgE, an autoimmune type IIb signature including the anti-TPO-to-IgE ratio, recurrent angioedema, inducible urticaria, treatment burden with high disease activity such as a UAS7 above 28, and symptom duration greater than 12 months before referral. Each variable was chosen because published evidence links it to disease persistence, severity, or treatment response, and each is measurable at the first specialist assessment. Weighting is deliberately equal, a recognized approach for provisional risk scores that reduces overfitting when derivation data are limited; regression-based weights will be estimated in planned validation studies. A retrospective cohort study at the authors’ centre is already scoring patients from first-presentation records and relating the totals to treatment response, time to control, corticosteroid exposure, and remission, with a prospective study planned to refine the thresholds and measure discriminative performance.

The authors are candid about the limitations. Existing prediction models lack prospective and external validation, most biomarker studies involve small observational cohorts, definitions of refractory disease vary between studies, and much of the evidence comes from tertiary referral populations subject to referral bias. The CLARITY framework, until validated, is hypothesis-generating only and should not guide individual treatment decisions. But the direction of travel is clear. The updated guideline introduced, for the first time, a dedicated question on biomarkers that predict disease course, formally placing prognosis on the research agenda. Integer risk scores of exactly this kind underpin cardiovascular medicine, and the review argues urticaria can follow the same path through prospective validation, multi-centre international cohorts, and eventually the integration of genomic, transcriptomic, and proteomic data with machine learning. If those efforts succeed, the patient walking into an allergy clinic with a fresh outbreak of hives could one day leave not just with a diary and a prescription, but with a credible estimate of the road ahead.

Subject of Research: Risk stratification and biomarkers for predicting difficult-to-control chronic spontaneous urticaria

Article Title: From disease activity scores to precision medicine: biomarkers and composite models for risk stratification in chronic spontaneous urticaria

Article References: From disease activity scores to precision medicine: biomarkers and composite models for risk stratification in chronic spontaneous urticaria. (n.d.). https://doi.org/10.3389/falgy.2026.1962595

Image Credits: AI Generated

DOI: 10.3389/falgy.2026.1962595

Keywords: chronic spontaneous urticaria, biomarkers, omalizumab, dupilumab, remibrutinab, autoimmune endotype, risk stratification, precision medicine, UAS7, angioedema, CLARITY framework, prognosis