Demodicidosis: The Eyes Have It

Manolette R Roque, MD, MBA, DPBO, FPAO

HEALTH First reported in 1840... Demodex folliculorum (all stages) is found in small hair follicles and eyelash hair follicles. In all forms, immature and adult, it consumes epithelial cells, produces follicular distention and hyperplasia, and increases keratinization leading to cuffing, which consists of keratin and lipid moieties. Demodex brevis (all stages) is present in the eyelash sebaceous glands, small hair sebaceous glands, and lobules of the meibomian glands. Adults and immature forms consume the gland cells in all of these loci and, when infestations are heavy, can affect the formation of the superficial lipid layer of the tear film coacervate. Demodectic mites produce histologically observable tissue and inflammatory changes, epithelial hyperplasia, and follicular plugging.

Infestation of the eyelash hair follicle results in easier epilation and more brittle cilia. These mites also serve as vectors of infective elements and interrupt tissue integrity. They have been implicated in meibomian granulomas and are associated with certain dermatologic changes. All reported histologic sections of lid follicles infested with D folliculorum show distention and thickening.

D folliculorum has been suggested as a factor in pityriasis folliculorum. This dermal inflammation manifests itself as a diffuse erythema of the affected areas; scaly, dry skin; and, in certain cases, rosacealike lesions. The dry skin cycle described by Ayres is initiated when the demodectic mite plugs the follicle and reduces the sebaceous outflow, which leads to scaling as well as rough and dry skin texture. Sebaceous outflow is further reduced when patients inadvertently decide to apply facial cream. The mite flourishes in this environment of oily additives, leading to an increase in the population of the mites and a continuation of the dry skin cycle.

The treatment regimen is divided into in-office care and at-home care. In the office, D folliculorum can be lured to the follicle surface with the use of volatile fluids... The home regimen includes scrubbing the eyelids twice daily with baby shampoo diluted with water to yield a 50% dilution and applying an antibiotic ointment at night until resolution of symptoms. Various treatments have been used to control Demodex mites. Most treatments involve spreading an ointment at the base of the eyelashes at night to trap mites as they emerge from their burrow and/or move from one follicle to another...

The latest popular treatment regimen includes the use of 50% tea tree oil with Macadamia nut oil, applied with cotton tip applicators, after one drop of tetracaine... Aggressively debride the lashes and the lash roots first with scrubs. Try to get the oil into the lash roots and along the lashes to kill any eggs. Treat the eyebrows as well... Home regimen includes the following:

  • Use tea tree shampoo on hair and eye lashes every day.
  • Use tea tree soap or face wash every day.
  • Buy new makeup and discard old makeup; do not use any makeup for 1 week.
  • Clean sheets and buy new pillows.
  • Check spouse; if both have this problem, both need to be treated.
  • Check pets.

For the first few weeks, use the ointment at night after tea tree shampoo scrubs. If inflammation is present, combination steroid-antibiotic ointments may be applied for one week. This is then replaced with a pure antibiotic ointment or with compounded 10% tea tree ointment.

Tags: clinical trial study, dermatological research, human, ophthalmologist, skin parasites


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