Ringworm of the scalp (tinea capitis)

Head | Dermatology | Ringworm of the scalp (tinea capitis) (Disease)


Description

Infection in the hair and scalp skin is associated with symptoms and signs of inflammation and hair loss (mainly in prepubertal children). The main signs are scaling and hair loss but acute inflammation with erythema and pustule formation can occur. Samples should be sent to laboratories with a particular interest and expertise in mycology. Microscopy provides the most rapid means of diagnosis, but is not always positive. Scalp scales and broken off hair stumps containing the root section (rather than intact hairs) are mounted in a 10±30% potassium hydroxide solution and viewed under the light microscope. Positive microscopy (when the hairs or scales are seen to be invaded by spores or hyphae) confirms the diagnosis and allows treatment to commence at once.

Causes and Risk factors

Tinea capitis, or scalp ringworm, is an exogenous infection caused by the dermatophytes Microsporum spp. and Trichophyton spp. These originate from a number of possible sources including other children or adults (anthropophilic), animals (zoophilic) or soil (geophilic). There is a wide range of clinical presentations and it can, particularly in mild cases, be very difficult to detect.

Diagnosis and Treatment

The treatment of choice by dermatologists is a safe and inexpensive oral medication, griseofulvin, a secondary metabolite of the fungus Penicillium griseofulvin. This compound is fungistatic (inhibiting the growth or reproduction of fungi) and works by affecting the microtubular system of fungi, interfering with the mitotic spindle and cytoplasmic microtubules.

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