Measles does not protect against asthma and allergies
MedWire News: Results from a South Korean study suggest that measles infection in early life does not protect against the development of asthma and allergies in childhood, and may even be associated with an increased risk for rhinitis.
Soo-Jong Hong (University of Ulsan College of Medicine, Seoul, South Korea) and team explain that the hygiene hypothesis proposes that infectious diseases in early childhood reduce an individual’s risk for developing allergic diseases in later life.
To investigate whether measles infection in early life is associated with lung function and reduced risks for allergic diseases, bronchial hyper-responsiveness (BHR), and allergic sensitization in later childhood, the team studied questionnaires completed by 1004 schoolchildren aged 6–7 years.
The children also underwent skin prick allergy tests, lung function tests, and methacholine challenge tests of airway reactivity, and had blood samples assessed for measles antibody titers.
The survey and tests were conducted 5 years after a major nationwide measles outbreak in South Korea, the researchers note in the Annals of Allergy, Asthma, and Immunology.
Overall, 8.2% of the children showed evidence of previous measles infection.
After adjustment for potential confounding factors, the researchers found that children with a history of measles, as identified through the questionnaire and measurement of antibody titers, were significantly more likely to have current rhinitis, a history of rhinitis symptoms, and current BHR than those without such a history, at odds ratios of 1.86, 2.17, and 1.98, respectively.
There was no significant difference between children with and without a history of measles regarding the prevalence of asthma, lung function measurements, allergic sensitization, or concentration of methacholine needed to cause a 20% decrease in FEV1.
Hong and team summarize: “Early measles infection was associated with increased prevalence of rhinitis and BHR at the age of 7 years but had no effect on the development of asthma and allergy at the age of 7 years.”
They conclude: “This study indicates that common childhood infections such as measles in early age do not protect against later development of allergic diseases.”
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By Mark Cowen