<http://schema.org/description>
"Allergies and your immune system are closely related to one another. Find out how your immune system can make you more susceptible to contracting an allergy."^^<http://www.w3.org/2001/XMLSchema#string>
<http://health.howstuffworks.com/diseases-conditions/allergies/allergy-basics/allergies-and-immune-system.htm>