Urticaria, Urticarial Vasculitis, Angioedema, and Related Diseases

Purpose of Review: Dermatologists are frequently called to evaluate patients with urticaria in the emergency room, urgent care clinics, and hospitals. Many acute urticarial eruptions will resolve without long-term sequelae; however, there are red flags that clinicians must be aware of. Recent Findings: First-line treatment for acute urticaria is regular dose H₁ antagonists; however, the dose can be increased up to fourfold for refractory disease. Short courses of corticosteroids should be avoided as rebound urticaria is common upon discontinuation. Urticarial vasculitis presents with persistent, atypical urticaria, burning, and residual lesions. The most common extra-cutaneous manifestation of urticarial vasculitis is musculoskeletal involvement. Schnitzler syndrome is a rare, severe condition but new evidence provides promise for use of biologic therapies. Summary: Acute spontaneous urticarial eruptions are commonly encountered in hospitalized patients. This review provides readers with the tools needed to delineate benign eruptions from more concerning conditions.