title: [Epidemiologic features in patients with antihistamine-resistant chronic urticaria].
abstract: BACKGROUND
  Current information on the particular features of patients suffering chronic spontaneous urticaria refractory to treatment is limited.
  
  
  OBJECTIVE
  To investigate demographic and clinical characteristics in patients with refractory chronic spontaneous urticaria.
  
  
  METHODS
  A retrospective analysis of the clinical and demographic information of patients consulting Allergy services from two hospitals in Caracas, Venezuela, who presented spontaneous urticaria lasting more than 6 weeks and did not respond to, at least, one course of treatment with antihistamines.
  
  
  RESULTS
  Refractory chronic spontaneous urticaria was frequent in Hispanic female patients aged 20 to 59 years, with moderate symptoms, individual lesions lasting less than three hours, and wheal diameters between 1 and 3 cm. Angioedema, alone or associated to urticaria was present in 14% of the patients. Most frequent comorbidities were asthma, rhinitis and rhinosinusitis, thyroid diseases and hypertension.
  
  
  CONCLUSIONS
  Refractory chronic spontaneous urticaria constitutes a highly prevalent subgroup of chronic urticaria which represents an important therapeutic challenge. This study did not demonstrate differential characteristics distinguishing refractory chronic spontaneous urticaria from chronic spontaneous urticaria patients who respond to the treatment with antihistamines.
authors.affiliation: Servicio de Alergología e Inmunología, Clínica El Ávila, Caracas, Venezuela. sanchezbmario@gmail.com.
authors.forename: Mario
authors.initials: M
authors.lastname: Sánchez Borges
authors.forename: Stefano
authors.initials: S
authors.lastname: Tassinari
authors.forename: Adriana
authors.initials: A
authors.lastname: Flores
keywords: angioedema; antihistamines; chronic urticaria; epidemiology