How Do Mites Affect Humans?

Hair mites can cause a variety of skin conditions in humans, ranging from rosacea to blepharitis, reports DermNet NZ. Dust mites, on the other hand, are major indoor triggers for individuals suffering from allergies and asthma, according to the American Lung Association.

Hair mites are microscopic parasites that come in two species, Demodex folliculorum and Demodex brevis, reports DermNet NZ. Folliculorum resides in hair follicles, especially in eyelashes. These mites are the primary culprit for blepharitis, which is a chronic inflammation of the eyelid. Demodex brevis lives in oil glands on the face and head and is responsible for a range of skin conditions. Perioral dermatitis, rosacea and pityriasis folliculorum are all skin conditions associated with increased numbers of mites.

Dust mites do not live on the human body but prefer to live off dead skin cells, according to the American Lung Association. Dust mite feces and body fragments are potent allergens. These mites reside in bedding, furniture, carpeting and drapery inside homes, and nearly four out of five American homes have detectable levels of dust mite allergens present. Unlike pet dander, dust mite allergens do not remain airborne. The dust mite allergen causes watery eyes and a runny nose after a brief exposure, but chronic exposure can result in facial pressure, coughing, congestion and serious asthma attacks.