Background: Urticarial vasculitis (UV) is a rare type of leukocytoclastic vasculitis characterized by long lasting urticarial skin lesions and poor response to treatment. As of yet, no clinical guidelines, diagnostic criteria, or treatment algorithms exist, and the approaches to the diagnostic workup and treatment of UV patients may differ globally. We conducted an online survey to examine how UV patients are diagnosed and treated by international specialists and to reveal the greatest challenges in managing UV patients worldwide.Methods: Distribution of the questionnaire included an email to individuals in the World Allergy Organization (WAO) database, with no restrictions applied to the specialty, affiliation, or nationality of the participants (November 2018). The email contained a link (Internet address) to the online questionnaire. Responses were anonymous. The link to the questionnaire was further sent to the network of Urticaria Centers of Reference and Excellence (UCARE) in the Global Allergy and Asthma European Network (GA 2 LEN) as well as to the Turkish Dermatology Society and the Japanese Society of Allergology, who distributed the link to their members. In addition, the survey link was posted online in the group of the Russian Society of Allergologists and Immunologists.
Results:We received 883 completed surveys from physicians in 92 countries. UV was reported to be rare in clinical practice, with an average of 5 patients per physician per year. More than twothirds of physicians reported wheals, burning of the skin, and residual hyperpigmentation in 60-100% of UV patients. The most frequently reported reason for receiving referrals of patients with UV was to establish the diagnosis. The most important features for establishing the diagnosis of UV were wheals of longer than 24 hours duration (72%), the results of skin biopsy (63%), and postinflammatory hyperpigmentation (46%). The most common tests ordered in UV patients were complete blood count, erythrocyte sedimentation rate, C-reactive protein, complement components, antinuclear antibodies, and skin biopsy. Physicians considered UV to be of unknown cause in most patients, and drugs and systemic lupus erythematosus to be the most common identifiable causes. Two of 3 physicians reported that they use second-generation antihistamines in standard dose as the first-line therapy in patients with UV. The greatest perceived challenges in the management of UV were the limited efficacy of drugs and the absence of clinical guidelines and treatment algorithms.