Canis ISSN: 2398-2942

Trichography (hair plucking)

Contributor(s): Karen Campbell, David Godfrey, David Scarff

Introduction

  • Hair examination is valuable aid to differential diagnosis of skin and hair disorders.
  • Useful technique - analysis for fungal diseases; parasitic diseases; congenital/hereditary diseases.
  • Differentiate self-trauma from other causes of hair loss/damage.

Uses

Definitive diagnosis

  • Self-inflicted (versus non self-inflicted) hair loss.
  • Trichorrhexis nodosa.
  • Pili torti.

Of diagnostic assistance in

Advantages

  • Easy technique.
  • Inexpensive.
  • Accurate.
  • Alternatives may be expensive, eg biopsy Biopsy: skin , fungal culture, and more invasive, eg biopsy.
  • For a definitive diagnosis of dermatophytosis it complements a positive culture as trichography (like biopsy) provides evidence of active infection while false positive cultures are possible due to contamination.
  • A fur pluck may be more readily collected than a scraping from certain patients and certain areas of the body, eg face or feet and may be adequate to diagnose (but not to rule out) demodicosis.

Disadvantages

  • Time consuming.
  • For dermatophytosis - does not provide information about the fungal species involved.
  • Dermatophyte infected hairs may be more readily detected on a scrape Scraping: skin from the area with infected hair fragments being picked up.

Requirements

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Preparation

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Procedure

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Aftercare

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Outcomes

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Further Reading

Publications

Refereed papers

Other sources of information

  • Miller W H, Griffin C E & Campbell K L (2013) Muller and Kirk's Small Animal Dermatology. 6th edn. Philadelphia: W B Saunders. p 81-83 (Detailed account with photographs of normal and abnormal hairs).
  • Moriello K A & Mason I S (1995) Handbook of Small Animal Dermatology.1st edn. Pergamon. pp 23-25 (Hair examination for fungal elements).


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