What is a Demodex mite on the face? - briefly
Demodex mites are microscopic, elongated arachnids that reside in hair follicles and sebaceous glands of facial skin, feeding on skin cells and oils. In small numbers they are harmless, but excessive growth may lead to irritation, redness, or acne‑like lesions.
What is a Demodex mite on the face? - in detail
Demodex mites are microscopic arthropods that reside in human hair follicles and sebaceous glands. Two species dominate facial colonisation: Demodex folliculorum, which occupies the superficial follicle, and Demodex brevis, which penetrates deeper into the glandular duct. Both complete a life cycle of egg, larva, two nymphal stages, and adult within 14‑16 days, after which the adult emerges to the skin surface to mate and lay new eggs.
The facial distribution concentrates on areas rich in sebaceous activity: eyelid margins, cheeks, nose, and forehead. Surveys reveal near‑universal presence in adults, with mite density rising markedly after the fourth decade of life.
When population control fails, the mites may provoke or aggravate dermatological disorders. Over‑infestation correlates with:
- rosacea‑type flushing and papules
- chronic blepharitis with lid margin irritation
- facial eczema, scaling, and itching
- cylindrical dandruff at the base of eyelashes
Diagnosis relies on standardized skin‑scrape or lash‑brush sampling examined under light microscopy. A count exceeding 5 mites per cm² of skin or 3 mites per lash is generally accepted as pathological.
Management strategies focus on reducing mite load and restoring skin barrier function:
- Topical agents: tea‑tree oil (5 % concentration), metronidazole 0.75 % cream, ivermectin 1 % lotion, applied twice daily for 4‑6 weeks.
- Oral therapy: ivermectin 200 µg/kg single dose, repeated after one week for resistant cases.
- Hygiene measures: daily gentle facial cleansing with non‑oil‑based products, regular laundering of pillowcases and towels, avoidance of heavy cosmetics.
Prevention emphasizes consistent skin care, minimisation of oily substances, and monitoring of underlying inflammatory conditions that may favour mite proliferation.