Demodex Hair Mites Infestation on Humans

by | Dec 13, 2018 | Health of Skin and Hair | 1 comment

Demodex mites are present in healthy individuals and may have a pathogenic role only when present in high densities.

This infestation may be clinically inapparent, but, under favorable circumstances, these mites may multiply rapidly, leading to the development of different pathogenic conditions.

 

What does ‘high population density of Demodex mites’ mean?

High population density means when the mites are reproduced at an increased rate by the resources on the host’s skin (e.g food and shelter), their numbers will sharply rise per inch. This is typically when host starts seeing symptoms of mite activity like skin or hair irritations.

 

Why hair mite population gets out of control?

Many of our clients who responded adversely to mites, reported that they had experienced high stress levels, or other medical conditions that would affect humans immune system.

A Demodex population density can soar very quickly when the immune system is unable to respond sufficiently to keep the mite population in check or because of their inflammatory response to microbe or waste products associated with the mites.

What harm can a high population density cause?

All cutaneous diseases caused by Demodex mites are clubbed under the term demodicosis or demodicidosis.

Although elevated levels of Demodex occur in such conditions, no studies have proven a definitive relationship.

It is possible that by blocking the hair follicles, it can cause inflammation or allergic reaction or act as vector for other microorganisms.

These conditions are briefly described below:

  • Rosacea and Demodex rosacea: Demodex may have a direct role in rosacea or may manifest as rosacea like dermatitis. Numerous studies have reported elevated Demodex density in patients with rosacea.
  • Non specific facial dermatitis: Patients presenting with nonspecific facial symptoms such as facial pruritus with or without erythema, a seborrheic dermatitis-like eruption, perioral dermatitis-like lesions and papulopustular, and/or acneiform lesions without telangiectasia, flushing, or comedones have been found to have significantly higher median mite density.
  • Steroid rosacea: The role of D. folliculorum in the pathogenesis of topical corticosteroid-induced rosacea is controversial. It has been reported that the population of Demodex mites is increased in these patients.
  • Androgenetic alopecia: Demodex has been implicated in the etiology of AGA. The role of Demodex in AGA has been evaluated to be direct in some studies and indirect in others.
  • Madarosis: Infestation of pilo-sebaceous components of the eyelids with D. folliculorum can also result in loss of eyelashes. Demodex mite causes follicular inflammation that produces edema and subsequent easier epilation of eyelashes.
  • Miscellaneous conditions: Increased number of Demodex mites has also been observed in peri-oral dermatitis, acarica blepharo-conjuctivitis, grover’s disease, eosinophilic folliculitis, papulovesicular facial, papulopustular scalp eruptions, pityriasis folliculorum, pustular folliculitis, Demodex abscess, and demodicosis gravis (granulomatous
    rosacea like demodicosis).

 

Prevention and treatment of human demodicosis

Demodex mite should be considered as an aetiological factor for a number of dermatoses for their early diagnosis and appropriate treatment.

Demodex can only live in the human hair follicle and, when kept under control, causes no problems. However, to reduce the chance of the mites proliferating excessively, following preventive measures are important:

  • Cleanse the face twice daily with non-soap cleanser
  • Avoid oil-based cleansers and greasy makeup
  • Exfoliate periodically to remove dead skin cells

After clinical manifestations, the mites may be temporarily eradicated with topical insecticides, especially crotamiton cream, permethrin cream, and also with topical or systemic metronidazole. In severe cases, such as those with HIV infection, oral ivermectin may be recommended.

 

You can read about the effects of Demodex mites here.

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