Humidity usually makes the symptoms worse, as the pollen get trapped in the moisture of the air and remains airborne for longer periods of time. The offending allergens are usually pollens, molds, dust mites and animal allergens. The CDC estimates that about 26 million Americans suffer from hay fever each year, with 17.5 million sufferers being 45 or younger. Allergic rhinitis is linked to chronic sinusitis, an inflammation of the facial sinuses, affecting some 35 million Americans. The National Institutes of Health's Office of Alternative Medicine is studying the use of complementary therapies, including oral immunotherapy, for hay fever and other allergies.
Symptoms tend to be primarily respiratory in nature.
Perhaps you only have problems when cleaning out a closet, or when spending long periods of time in a damp basement, or when cleaning the bathroom. Molds can be found both indoors as well as outdoors. Raking leaves or turning a mulch pile can be particularly irritating. Using a filter mask when performing these activities can lessen their negative effects. Dust mites are especially problematic, as the irritating particles are very small, and get everywhere.