Uncovering the Autoimmune Links & Systemic Impact of Chronic Spontaneous Urticaria

When recurrent urticaria persists beyond 6 weeks, clinicians should consider chronic spontaneous urticaria (CSU), a condition increasingly recognized as having autoimmune and autoallergic mechanisms. Nicholas Brownstone, MD, a board-certified dermatologist at Mount Sinai in New York City, met with Dermatology Times to discuss the clinical features and broader impact of CSU.

CSU may involve type I autoallergic mechanisms, in which the immune system reacts to targets such as thyroid peroxidase or IL-24, or type II autoimmune mechanisms involving IgG autoantibodies that activate mast cells. The association with autoimmune disease is clinically relevant: up to 30% of patients with CSU may have at least 1 autoimmune condition. Hashimoto thyroiditis is among the most common, affecting up to 20% of patients in some reports. A large retrospective cohort of approximately 13,000 patients found that 17% had an autoimmune disease, including rheumatoid arthritis, Sjögren syndrome, celiac disease, and type 1 diabetes. Given this association, Brownstone recommended that dermatologists consider screening for thyroid abnormalities with TSH testing and asking patients about personal and family histories of thyroid disease.

The impact of CSU also extends beyond the skin. The unpredictable nature of flares and significant pruritus can substantially impair quality of life, sleep, and mental health. Brownstone noted that a recent JAMA review found anxiety and depression rates of up to approximately 30% among patients with CSU. He advocated routinely asking patients with potentially impactful skin diseases whether their condition is affecting their mental health or quality of life. For patients who report a significant impact, clinicians can consider counseling or more aggressive treatment of the underlying dermatologic disease.

Brownstone also distinguished CSU from chronic inducible urticaria (CIndU), in which hives can be reproducibly triggered by external stimuli such as cold, pressure, heat, sweating, stress, sunlight, vibration, or water. Unlike CSU, CIndU generally produces shorter-lasting wheals, sometimes resolving within an hour. Diagnosis is primarily based on the patient's history. Although there are currently no FDA-approved therapies specifically for CIndU, Brownstone noted that agents including dupilumab, remibrutinib, and omalizumab may be used off-label, with additional therapies potentially expanding treatment options in the future.