Increasingly, indoor molds are being recognized as a triggering factor of allergic reactions. Mold grows in damp environments: near water leaks in basements, in humid corners of old houses, in bathrooms that never quite dry out. Humidifiers can also disperse mold if not cleaned properly. If Jimmy suffers from unexplained nasal allergies and has constantly tearing eyes, nasal secretions, and an itchy nose, he could be reacting to mold in your house. The same goes for unexplained recurring episodes of hives and asthma.
That said, don’t jump to conclusions too quickly. These respiratory symptoms could simply be due to a recurring cold [See: Colds]. Unfortunately, proving the allergic connection will be difficult, since skin tests for mold aren’t very reliable. If you suspect mold allergy, look for humid, moldy spots in your house and clean them up as best as you can.