Which histologic findings are characteristic of tinea capitis (scalp ringworm)?

Updated: Feb 21, 2020
  • Author: Marc Zachary Handler, MD; Chief Editor: Dirk M Elston, MD  more...
  • Print
Answer

Fungi are seen sparsely in the stratum corneum (see the first image below). Hyphae extend down the hair follicle, growing on the surface of the hair shaft. Hyphae then invade the hair, penetrate the outermost layer of hair (ie, cuticle), and proliferate downward in the subcuticular portion of the cortex, gradually penetrating deep into the hair cortex. Pronounced inflammatory tissue reaction with follicular pustule formation surrounding hair follicles is seen in patients with the clinical form of infection termed kerion celsi (see the second image below).

Fungal hyphae and yeast cells of Trichophyton rubr Fungal hyphae and yeast cells of Trichophyton rubrum seen on the stratum corneum of tinea capitis. Periodic acid-Schiff stain, magnification 250X.
Pronounced inflammatory tissue reaction with folli Pronounced inflammatory tissue reaction with follicular pustule formation surrounding a hair follicle seen in a patient with clinical form of infection, termed kerion celsi. No fungal hyphae or spores were identified in the lesion in either tissue sections or culture. Fluorescein-labeled Trichophyton mentagrophytes antiserum cross-reacted with antigens of dermatophyte in the infected hairs within the pustule (hematoxylin and eosin stain, magnification X 75).

In endothrix infection, spherical–to–box-like spores are found within the hair shaft. This type of infection is caused by T tonsurans or T violaceum.

In ectothrix infection, organisms form a sheath around the hair shaft. In contrast to endothrix infection, destruction of the cuticle by hyphae and spores occurs.


Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!