tinea%20capitis
TINEA CAPITIS
Tinea capitis  is a contagious dermatophytosis affecting the hair shaft and follicles of the scalp, eyebrows and eyelashes.
It is most common in the crowded areas as infection originates from contact with a pet or an infected person and asymptomatic carriage persists indefinitely.
It primarily affects children 3-7 years of age.
The causative agents are the genus Trichophyton and Microsporum.
Cardinal clinical feature is the combination of inflammation with hair breakage and loss.

Diagnosis

  • All specimens obtained (scalp scrapings, hair follicles) should undergo microscopy & culture, w/ causative organism identified

Laboratory Tests

Microscopy

  • Provides the most rapid means of diagnosis but may not always be positive in affected patients
  • Scalp scales &/or hair are mounted in 10-30% potassium hydroxide (KOH) solution, gently heated & viewed under light or flourescence microscope
  • Positive results reveal hairs and scales invaded by spores &/or hyphae

Causative Agents

  • Large-spored endothrix pattern chains of large spores within hair (Trichophyton tonsurans, T violaceum)
  • Large-spored ectothrix (T verrucosum, T mentagrophytes)
  • Small-spored ectothrix randomly arranged in masses inside & on the surface of the hair shaft (Microsporum canis, M audouinii)

Dermoscopy (Trichoscopy)

  • A noninvasive in vivo imaging technique that may aid in the diagnosis of Tinea capitis, especially in patients w/ black dot pattern

Culture

  • Allows accurate identification of organism but results may take up to 4 weeks
  • Use of Sabouraud agar w/ 1 or more plates w/ cycloheximide is recommended
  • Results may be positive even when microscopy is negative
  • Necessary in hair fungal infections to identify the source of infection & verify the infecting species

Wood’s Light Exam

  • Useful for certain ectothrix infections (eg M canis, M audouini, M rifalieri)
  • If present, will cause hair to fluoresce bright green
  • T tonsurans which causes most Tinea capitis does not fluoresce
Digital Edition
Asia's trusted medical magazine for healthcare professionals. Get your MIMS Infectious Diseases - Malaysia digital copy today!
Sign In To Download
Editor's Recommendations
Most Read Articles
07 Jun 2019
Podcast: Professor Oliver Distler talks about the utility of nintedanib in ILD in the SENSCIS trial
07 Jun 2019
Slideshow: Highlights from the American Thoracic Society 2019 (ATS 2019) International Conference
17 Dec 2018
At the 40th Malaysian Paediatric Association Annual Congress held on 6 September 2018 at the Ipoh Convention Centre, Dr Yong Junina Fadzil discussed the applications of a hexavalent vaccine in optimizing paediatric vaccination schedules. Meanwhile, Dato’ Dr Musa Mohd Nordin shared his insights into the paediatric influenza ‘landscape’ in the region and highlighted the importance of regularly vaccinating paediatric patients.