Epidemiology

In this section of the Knowledge Centre, we explore the prevalence and duration of urticaria, including the risk factors for increased time with the condition. The burden of disease is also explored, with consideration of the impact on quality of life, daily functioning and socioeconomic factors. You can also learn more on the epidemiology of chronic urticaria from Professor Marcus Maurer, filmed at EAACI 2019.

Prevalence

One in every 200 adults in the five largest countries in the EU has been diagnosed with chronic urticaria, and 40% of them are currently using a prescription treatment (Balp M-M et al., 2015).

Urticaria is more common than previously thought. Chronic urticaria (CU) affects up to 1% of the population at any given time and Chronic Spontaneous Urticaria (CSU) accounts for two thirds of the cases (Balp et al., 2015; Maurer et al., 2011), evidence suggests prevalence may be increasing  (Hellgren, 1972; Gaig et al., 2004; Zuberbier et al., 2010; Zazzali et al., 2012; Lapi et al., 2016). CSU lifetime prevalence estimates range from 0.6% to 1.8% (Gaig et al., 2004; Zuberbier et al., 2010).

Terminology

Lifetime prevalence is the proportion of a population that at some point in their life (up to the time of the assessment) have experienced the condition.

 

Chronic spontaneous urticaria (CSU) as a percentage of chronic urticaria cases and the ratio of male to female CSU sufferers.

Figure 1. CSU as a percentage of chronic urticaria cases and the ratio of male to female CSU sufferers.
1, Maurer et al., 2011; 2, Kozel et al., 1998; 3, Sani, 2009.

Although all age groups can be affected, the peak incidence is seen between 20 and 40 years of age (Maurer et al., 2011). There is no apparent correlation of prevalence with education, income, occupation, place of residence or ethnic background. To find out more on chronic urticaria in the Asian population, watch the EAACI 2019 presentation by Professor Zuotao Zhao here.

The majority of patients have no evidence of any exacerbating factor, however a recognised trigger for CSU is nonsteroidal anti-inflammatory drugs (Ferrer et al., 2015).

A population-based study on the epidemiology of CSU in Italy over a 12-year period (2002–2013) demonstrated that the risk of CSU was statistically significantly higher in the presence of the following variables (Lapi et al., 2016):

  • Obesity
  • Anxiety
  • Dissociative and somatoform disorders
  • Malignancies
  • Use of immunosuppressive drugs
  • Chronic use of systemic corticosteroids
     

Duration

Terminology

Lifetime prevalence is the proportion of a population that at some point in their life (up to the time of the assessment) have experienced the condition.

 

CSU has a duration of at least 1 year in most patients and more than 5 years in a considerable proportion. In very rare cases it can last up to 50 years (Maurer et al., 2011; Toubi et al., 2004; Mlynek et al., 2009; Gattey et al., 2015; Beck et al., 2017).

The percentage of patients with chronic spontaneous urticaria (CSU) symptoms at 6 months, 3 years, 5 years and 25 years after their initial diagnosis.

Figure 2. The percentage of patients with CSU symptoms at 6 months, 3 years, 5 years and 25 years after their initial diagnosis (Beltrani, 2002).

The evolution of CSU is unpredictable, with spontaneous remissions and relapses (Ferrer M et al., 2015).  At least 50% of CSU patients will experience at least one recurrence of CSU symptoms after an apparent resolution (Hellgren L, 1972).

 

Prognostic factors for the duration of CSU

The duration of CSU is generally longer in patients with:

  • More severe disease (Maurer et al., 2011; Toubi et al., 2004)
  • Concurrent angioedema (Maurer et al., 2011; Toubi et al., 2004)
  • Concurrent inducible urticaria (Maurer et al., 2011; Kozel et al., 2001)
  • A positive autologous serum skin test (ASST) or autologous plasma skin test (APST) (Maurer et al., 2011; Staubach et al., 2006; Boonpiyathad & Sangasapaviliya, 2016)

The autologous serum skin test (ASST) is a screening test for autoantibodies in CSU.

Diagnosis is based on a thorough medical history and physical examination as well as diagnostic tests. Read about the diagnostic markers of which to be aware.