At Skin of Color Update 2025, Mona Shahriari, MD, FAAD, provided a comprehensive overview of chronic spontaneous urticaria (CSU). CSU is a condition frequently managed by both dermatologists and allergists. Dr. Shahriari challenged dermatologists to embrace CSU as a condition that can be confidently managed without necessitating a referral.
CSU affects about 1% of the population, with a prevalence of 230 per 100,000 adults. It is most common in individuals 20–40 years old, and some data suggests a higher prevalence in Black populations in comparison to White populations. CSU is defined by the presence of itchy wheals (hives) and/or angioedema for at least six weeks, with individual hives lasting less than 24 hours and angioedema up to 72 hours. And by definition, there must be no identifiable trigger.
The disease is mast cell-mediated, with a rapid onset of symptoms when triggered. The pathogenesis of CSU can be likened to a piñata. When a mast cell is triggered, it’s as if the pinata is hit, and now all the proteins, like histamine, that are inside the mast cell, pour out, akin to candy pouring out of a pinata.
There are several comorbid conditions that can occur concomitantly with CSU with autoimmune thyroid disease being one of the most common. Interestingly, females with CSU have a 20-fold increased risk for rheumatoid arthritis and hypothyroidism at 10 years. Vitiligo, type 1 diabetes, pernicious anemia, and atopic diseases are other comorbidities that are commonly seen in patients with CSU.
CSU is an often misunderstood skin disease that disproportionately affects quality of life, especially in patients with skin of color, where diagnosis and management can be uniquely challenging. The clinical features of wheals and angioedema are consistent across skin types, but erythema is less visible in skin of color, making diagnosis more difficult. Videos may be more useful than photos for assessing lesion elevation in these patients.
The burden of CSU is substantial, with up to 40% of patients experiencing a very large negative impact on quality of life, including sleep disturbance, anxiety, and depression. Itch is the most burdensome symptom.
Diagnosis is clinical. International guidelines recommend a focused history, symptom assessment, and limited laboratory workup (CBC and ESR/CRP, with the option of anti-thyroid peroxidase IgG, and IgE levels when indicated). Extensive allergy testing and biopsy are not required unless atypical features are present. In those instances, the additional work up would be to rule out other conditions, not rule in CSU.
Diagnostic delays are common, with patients often symptomatic for 2–3 years before diagnosis, partly due to the intermittent nature of CSU. Patients are frequently referred to multiple clinicians and cycle through various antihistamines and corticosteroids before finally getting the correct diagnosis. The differential diagnosis is broad and includes urticarial vasculitis and bullous pemphigoid. The transient nature of CSU lesions (<24 hours) is a key distinguishing feature.
Management should be proactive and guideline-driven. The goal of treatment should be to control the disease, not cure it. Second-generation H1-antihistamines are first-line, with dose escalation if needed. If symptoms persist, omalizumab, dupilumab, and remibrutinib are appropriate second-line agents to consider. Dupilumab, which has been used by dermatologists to treat atopic dermatitis since 2017, is an appealing first-line option, since dermatologists are familiar with its dosing and safety. There are various other mediations that are being studied in the management of CSU. Dr. Shahriari dispelled existing safety concerns regarding the use of omalizumab, emphasizing that anaphylaxis is very rare and was only seen in the asthma trials, a population which is at higher risk at baseline, and was not seen in urticaria trials. Of note, data suggested that patients with skin of color are less likely to receive omalizumab, which clinicians need to be aware of to ensure equity in disease management.
In summary, recognizing the nuances of CSU in skin of color, especially the subtlety of erythema and the importance of video documentation, can improve diagnostic accuracy and patient outcomes. Dermatologists should avoid cycling through multiple antihistamines and have a low threshold to consider advanced targeted therapies for CSU, like dupilumab, remibrutinib and omalizumab. Prednisone should be avoided and only used as a short-term bridge in unique circumstances, not as monotherapy. With the latest developments in the CSU space and the approval of medications that we are dermatologists are quite familiar and comfortable with, dermatologists should feel empowered to take back ownership of this disease to optimize outcomes for patients.
This information was presented at the 2025 Skin of Color Update conference by Mona Shahriari, MD, FAAD. The above highlights from this lecture were written and compiled by Jay Nguyen, DO.
