While you drift into slumber each night, numerous tiny creatures called demodex mites emerge from your skin to roam about. These microscopic, eight-legged arachnids, measuring between 0.15 and 0.4 millimetres, inhabit hair follicles and feast on the oils our skin produces. According to Alejandra Perotti, an invertebrate biology associate professor, they are most active whilst we sleep, engaging in mating and exploration, retreating back into our pores upon waking.
Despite the unsettling notion of these mites, Perotti assures us they are generally harmless. In fact, they help cleanse our pores while relying on melatonin, a hormone that aids our sleep, for nourishment. Interestingly, these mites have adapted to avoid damaging ultraviolet rays from the sun.
Typically, each square centimetre of our face hosts around five of these mites, invisible to the naked eye. However, if one’s immune system weakens — such as in older adults or those undergoing chemotherapy — these mites can multiply excessively, leading to skin conditions like acne or rosacea. Research by experts like Dr. Richard Locksley and Dr. Roberto Ricardo-Gonzalez indicates that certain individuals may react negatively to the mites, which are absent in wild animals but common in domesticated pets, hinting at a potential evolution-related vulnerability.
Skin irritations caused by demodex can result in symptoms like dryness, itchiness, and inflammation. Diagnosing issues related to these mites typically requires a dermatological examination. To maintain healthy skin, consulting a healthcare professional is advisable rather than attempting to self-diagnose.
For most healthy individuals, there is no need for concern. Locksley emphasises that people should remain unaware of the mites and avoid unnecessary interference. Good hygiene practices are beneficial, including cleaning the face thoroughly before bed to remove excess oil and debris.
To prevent mite overgrowth, a consistent skincare routine is recommended, featuring mild cleansers and potentially topical retinoids for acne-prone skin. Healthy sleep habits are crucial too, as sleep deprivation can lead to increased oil production and create an inviting environment for the mites.
Although treating excessive populations might require medical intervention, including topical or oral ivermectin, complete eradication of these mites is impossible. They have coexisted with humans for centuries, likely transmitted through maternal contact at birth. However, studies suggest that demodex might be facing evolutionary decline, leading to potential extinction due to inbreeding and a lack of genetic diversity.
Perotti notes that while they have been blamed for numerous skin issues, underlying immune system problems are often the true cause. She advocates for a more compassionate view of these mites, acknowledging their role as companions rather than foes in our skin’s ecosystem.