Diagnostic and treatment trends in chronic urticaria. Retrospective and prospective analysis of patients from the Department of Dermatology, Medical University of Poznan

Introduction
Confirmation of the cause of chronic urticaria (CU) seems a great challenge for specialists. The aim of pharmacological treatment is to reduce the effect of mediators released from mast cells on target organs and to reduce symptoms.
Aim: To analyse the diagnostic and treatment trends in CU.

Material and methods
The study was divided into two parts. Retrospective (R) analysis included 441 CUpatients at the age of 15 or older hospitalized during 10 years. Information from history of the disease was entered in a specially designed form. For the prospective (P) analysis 78 patients were chosen out of 441 subjects previously qualified for retrospective analysis. Patients from the P part were divided into subgroups I and II in terms of persistence of symptoms.

Results
The most frequently performed tests were the aspirin test (79.6%), autologous serum skin test (ASST) (79.4%) and provocation by pressure (70.7%). Significant differences concerning the type of urticaria, in which an increased C-reactive protein level was detected the most frequently, were found in spontaneous, autoimmune and aspirin-induced urticaria. There was observed a significant increase in the frequency of the determination of thyroid hormones and anti-thyroid antibodies over the years. Most frequently the patients received second-generation antihistamines (63% R; 88.4% P). There was reported less usage of first generation of antihistamines over the years (from 27.9% to 3.7%). The cause of symptom relief in subgroup II was mainly pharmacotherapy (37.1%).

Conclusions
The obtained results agreed with most reports concerning diagnosis and treatment of CU.