<p>Chronic spontaneous urticaria (CSU) can cause unpredictable, distressing hives and angioedema that can go undiagnosed or untreated for years, impairing patient quality of life. Inadequate therapies, poor awareness, and fragmented care pathways contribute to the disease burden. New treatments and a better, more global understanding of the impact of CSU offer hope for improved patient outcomes.</p>

CSU can often go undiagnosed or, at a minimum, undertreated. In my experience, up to 50% of patients with the disease experience spontaneous remission within 1 year. However, the longer a person has it, the less likely it is that it will remit, and there are patients who can have CSU for a lifetime. CSU that presents with angioedema can contribute to a greater disease burden, as angioedema can have an even higher psychosocial impact due to its potential to cause temporary physical deformation and the fear of life-threatening airway obstruction.

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The unpredictability of CSU (ie, going from nothing to having full-blown symptoms) really contributes to its unique burden and impact on quality of life. While hives are so visible and palpable in more ways than one, they are defined by their ephemeral nature. It is important to remember that an individual CSU plaque should only last for approximately 24 hours (if we are pushing it, up to 36 hours at most), while the overall activity of a flare can last for weeks. Therefore, how you solicit this information from patients is important because ambiguous questions can contribute to missing the diagnosis (eg, how long will a single spot last vs how long does this last?). We also need more physician- and patient-facing education to get patients with CSU to the right place, whether that is allergy/immunology or dermatology. Misinformation about what the disease is and where to go can delay care and add to the disease burden.

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Having suboptimal or limited therapeutic options for CSU also increases the disease burden. First-line therapies are nonsedating second-generation antihistamines, but anywhere from 30% to 50% of patients with CSU do not respond to updosing to 4-fold the recommended dose. Until recently, the only US Food and Drug Administration (FDA)–approved advanced medication for CSU was omalizumab, but approximately 25% to 30% of patients may not have an adequate response to optimized dosing. Therefore, a good subset of individuals are not getting relief, which certainly affects the patient.

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As for comorbidities, there are many (especially type 2 inflammatory comorbidities), but let us focus on a common and very relatable one: sleep. Uncontrolled CSU can impact sleep, which has immediate and downstream health consequences, as well as influences on daily life that can lead to both absenteeism and presenteeism at school and/or work. Switching gears, another “comorbidity” of CSU is the financial cost. Just because antihistamines are available over the counter does not mean that they are inexpensive (and recall that we often recommend updosing to 4-fold the recommended dose that is listed on the bottle). Further, the well-described physician hopping from primary care to urgent care to the emergency department to specialist care also comes with significant costs, including social costs such as missed opportunities with friends and family.

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There is an ongoing effort to hear the voices of patients with CSU and to understand the impacts of the treatments that are currently available, as seen in the AWARE study. I also think that it is important for dermatologists to be aware of research tools that are being employed in clinical trials and global studies to assess disease severity and develop a shared language with providers, patients, and payers. For example, we have the weekly Urticaria Activity Score (UAS7) and the Urticaria Control Test (UCT). While I prefer the UCT because of its simplicity (it only has 4 questions), it covers a 4-week period as opposed to a 1-week period like the UAS7 and is thus subject to a greater recall bias. That said, we need to be aware of the validated tools used in clinical trials for new therapies, as we will need to document using language the payers uniformly understand and in which they are fluent.

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All in all, to best support and partner with our patients with CSU, we must be prepared to address all facets of the disease, from timely and accurate diagnosis to patient education to guideline-based treatment escalation, while recognizing and acknowledging the unique psychosocial burden of disease.