Allergic disorders are an increasing health problem, in particular among children.
This study evaluated the prevalence and manifestations of allergy in a cohort of 180 children from Iceland for more than 20 years - at the ages of 2, 4, 8, 15, and 21 years.
Cumulative prevalences were:
- 40% for rhinoconjunctivitis
- 45% for eczema
- 29% for asthma
None had developed rhinoconjunctivitis at the age of 2 years, but the point prevalence gradually increased to 33% at the age of 21 years.
Conversely, the prevalence of eczema was 31% at the age of 2 years, but gradually declined to 8% at the age of 21 years.
Allergic (atopic) march (click here to enlarge the image):
The prevalence of asthma peaked at 28% at the age of 4 years, but declined thereafter and has remained stable at about 13% from the age of eight to 21 years.
The prevalence of allergic diseases is high in Iceland. Asthma and atopic eczema are very common in childhood, but decreases with age while the prevalence of rhinoconjunctivitis increases markedly.
The very high and increasing prevalence of rhinoconjunctivitis among 15- to 21-year-old individuals is noteworthy.
Finnbogadóttir AF, Árdal B, Eiríksson H, Hrafnkelsson B, Valdimarsson H, Lúðvíksson BRúnar, Haraldsson Á. A long-term follow-up of allergic diseases in Iceland. Pediatr Allergy Immunol 2012 Doi: 10.1111/j.1399-3038.2011.01234.x