Humidifiers can be helpful for adults and kids who have allergies and whose sinuses are aggravated by dry air. Although humid air can offer short-term relief for irritated sinuses, allergens like mold and dust mites can thrive in air that is too humid or humidifiers that aren't cleaned regularly. Be sure to follow the manufacturer's recommendations for the best allergy-relieving results. Both warm mist and cool mist humidifiers can provide allergy relief, it's up to personal preference which you choose to use. If you're looking for the best humidifiers for allergies, check out these products from retailers like Amazon, Walmart and Target.