Eczema and Urticaria in the Adult Population in Portugal: A Prevalence Study

Background and aims: Eczema and urticaria are both inflammatory skin diseases. The prevalence of both diseases varies worldwide and the reasons are unknown. We aimed to investigate the eczema and urticaria prevalence in the Portuguese adult (≥16 years-old) population.

Materials and methods: A telephone interview survey was performed in the last quarter of 2017. To calculate the prevalences, subjects should have been previously diagnosed with eczema/urticaria by a health professional, be aged ≥16 years-old, and reside in Portugal. The sample had a proportion that was approximately representative by population, region, gender, and age group. Odds ratios were performed to measure associations with prevalences. SPSS statistics and values of p<0.05 with 95% confidence intervals were considered statistically significant.

Results: 5,000 phone calls were analysed. The prevalence of eczema and urticaria in Portugal is 4.4% and 3.4%, respectively. Algarve is the region with the highest prevalence for both diseases. Being a female is the factor that most influenced these diseases with an OR=1.99 (p<0.001; CI 1.49-2.66) for eczema and 1.73 (p=0.001; CI 1.25 - 2.40) for urticaria, with also higher prevalences (5.7% and 4.2%, respectively).

Conclusions: The prevalences found are higher than in previous studies in Portugal and comparable to results from other countries. Comparisons among prevalence of eczema are affected by several obstacles. Regarding urticaria, our results seem to be in the same line as others. Being female with eczema and urticaria is more common and represents a higher risk factor than male subjects. According to Harrop et al., 2007, in Europe, atopic eczema is 0.14-0.60% of general eczema. In this way, we can estimate that prevalence of atopic eczema in Portugal is around 0.61-2.64%.