Pathogenic role of Demodex mites in blepharitis

Curr Opin Allergy Clin Immunol. 2010 Oct;10(5):505-10. doi: 10.1097/ACI.0b013e32833df9f4.

Abstract

Purpose of review: To summarize the key literature and our research experience regarding Demodex infestation as a potential cause of ocular inflammatory diseases with a special emphasis on Demodex blepharitis.

Recent findings: Two distinct Demodex species have been confirmed as a cause of blepharitis: Demodex folliculorum can cause anterior blepharitis associated with disorders of eyelashes, and D. brevis can cause posterior blepharitis with meibomian gland dysfunction and keratoconjunctivitis. Tea tree oil treatments with either 50% lid scrubs or 5% lid massages are effective in eradicating mites and reducing ocular surface inflammation.

Summary: Demodex blepharitis is a common but overlooked external eye disease. The pathogenesis of Demodex blepharitis in eliciting ocular surface inflammation has been further clarified. The modified eyelash sampling and counting method makes it easier and more accurate to diagnose Demodex infestation. Tea tree oil shows promising potential to treat Demodex blepharitis by reducing Demodex counts with additional antibacterial, antifungal, and anti-inflammatory actions.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Blepharitis / drug therapy
  • Blepharitis / etiology*
  • Blepharitis / physiopathology
  • Conjunctiva / immunology*
  • Eyelashes / pathology
  • Humans
  • Hypersensitivity, Delayed / complications*
  • Hypersensitivity, Delayed / drug therapy
  • Hypersensitivity, Delayed / physiopathology
  • Inflammation
  • Keratoconjunctivitis
  • Meibomian Glands / pathology
  • Mite Infestations / complications*
  • Mite Infestations / drug therapy
  • Mite Infestations / physiopathology
  • Mites / immunology*
  • Tea Tree Oil / therapeutic use

Substances

  • Tea Tree Oil