Mold allergies are the result of an over-reaction by your immune system. Mold, which is a type of fungus, reproduces by releasing spores into the air. When you breathe in those spores, your body thinks it's being invaded by something harmful. Its reaction ends up causing you discomfort in the form of sneezing, a runny nose, itchy and watery eyes and the like. There are a few ways to treat mold allergies, though.
Nasal corticosteroid sprays can help reduce the inflammation in your nose that's caused by the spores that land in there. The sprays are considered safe for long-term use, with the most likely side effect being nosebleeds. Another helpful treatment for mold allergies is the use of antihistamines. Since histamine is released by your body as it fights the allergens, it makes sense to use drugs that block those histamines and the uncomfortable symptoms they cause. Antihistamines can reduce itching, runny noses and sneezing. They're available in pill form and in nasal sprays; the only downside is that some of them can make you sleepy.
Decongestants are medications used to help reduce the stuffiness in your nose and help you breathe more easily. You can take them orally or through a nasal spray, but the nasal spray can't be used for more than a few days in a row. Drugs like cromolyn are used in the same way as antihistamines, and montelukast is a type of drug that stops leukotrienes, which are the chemicals your immune system uses to produce extra mucous. Nasal saline sprays are used to wash out your nose to get rid of allergens that may be sitting there. Immunotherapy, or allergy shots, is a long-term treatment for allergies, although it's not considered completely effective against mold allergies. However, as with all allergies, the best cure for mold allergies is prevention.