1 Demodex and skin health Domina Petric, MD ABSTRACT Aim is to discuss the connection of Demodex spp. infestation of the skin with various types of skin disorders, especially acne and seborrheic dermatitis. Patients with demodicosis might be successfully treated with local antiparasitic agents in combination with keratolytic agents, sebo- regulators, antibacterial and antifungal agents. INTRODUCTION Demodex is a genus of tiny mites that live in or near hair follicles of mammals 1 . Two species live on humans: Demodex folliculorum and Demodex brevis, both frequently referred to as eyelash mites. D. folliculorum is found in hair follicles, while D. brevis lives in sebaceous glands connected to hair follicles. Both species are primarily found in the face, near the nose, the eyelashes, and eyebrows, but also occur elsewhere on the body 2 . DEMODICOSIS Demodex were considered commensals but are now considered parasitic. However, in the vast majority of cases the mites go unobserved without any adverse symptoms, though in certain cases (usually related to a suppressed immune system, caused by stress or illness), mite populations can dramatically increase. This results in a condition known as demodicosis or Demodex mite bite, characterised by itching, inflammation, and other skin disorders. Blepharitis (inflammation of the eyelids) can be also caused by Demodex mites 3, 4 . Demodex has been associated with the development of pityriasis folliculorum, rosacea 5-7 , perioral dermatitis 8 , seborrheic dermatitis 9 , pustular eruption 10 , blepharitis 11, 12 , seborrheic alopecia 10 , the dermatosis that persists and shows a resistance to classical therapies 13 and acne 13-15 . DEMODICOSIS AND ACNE Post adolescent acne is generally mild to moderate in severity and presents with more inflammatory lesions and fewer comedones when compared to adolescent acne. The aetiopathogenesis of post