D2.233 - Epidemiology, Patient Characteristics, and Treatment Responses of Chronic Urticaria in Türkiye: A Systematic Literature Review

The objectives of this study are to present the epidemiology of chronic urticaria in Türkiye, disease phenotypes, patient characteristics, patient responses to treatment, and an overview of clinical studies. The following research questions were identified to address the objectives:

1.What is the epidemiology, disease phenotypes and patient characteristics of CU in Türkiye? 2.What are the treatment response rates of CU treatments in Türkiye? 3.What are the results of clinical studies of CU in Türkiye? 4.What are the antihistaminic response rates in CU treatment in Türkiye

A Sstematic Literature Review, following the PRISMA 2020 approach was used in the study. The review encompassed studies published between January 1, 2005, and December 31, 2024. Theoretical publications, comments, letters to the editor, newspaper articles, conference abstracts and publications other than English and Turkish were excluded from the study. After searching all databases with the predetermined key words, duplications were removed and the abstracts of the remaining articles were thoroughly analyzed with the exclusion and inclusion criteria. The selection of studies to be included in the SLR was finalized in a meeting with experts.

•No studies have investigated the epidemiology of CU in Türkiye at either the national or provincial level.•According to expert opinions, 20% of the general population in Türkiye have urticaria and 0.3% have CSU. Among these patients, 50% have mild CSU, 40% have moderate CSU and 10% have severe CSU. The average duration of treatment for CSU patients is 2 years.•The majority of the patients in the studies were female (60-70%), with a mean age between 30-45.•The average age of disease onset was around 30 years, and the duration of the disease ranged from11-82 months.•Triggering factors identified included smoking, food and food additives, drugs, stress, infections, and parasites.•Having a family member with an allergic disease or urticaria was also noted as a possible risk factor.•Angioedema was found to accompany 50-90% of patients. The most common comorbidity was atopy (15-45%). Autoimmune thyroid diseases were highlighted as significant comorbid condition.•Urticaria patients often experience depressive symptoms, anxiety, sexual dysfunction, and sleep problems.•The most common subtypes of chronic inducible urticaria were symptomatic dermographism followed by cold urticaria and cholinergic urticaria.•The duration of the disease and baseline disease activity were identified as important determinants of treatment response.•Among the studies focusing on treatment, 78% investigated omalizumab treatment, with response rates ranging from 30% to 75%.•Serum total IgE levels and the urticaria activity score were found to significantly influence treatment response and prognosis.

An important finding of this study is the lack of epidemiological studies on CU at a national level and in specific regions. Epidemiological data is crucial for policy-makers to make informed decisions about resource allocation. This data is also essential for health economics and outcomes research. Other findings of the study are consistent with global research results.