Tinea capitis

This is usually seen in pre-adolescent children. Adult cases are rare. The key symptoms are scalp hair loss and scaling. Sometimes there is a black-dot pattern (studded with broken-off hairs) (Figure 12.7). Acute inflammation with erythema and pustule formation may also occur. Infection may also be associated with painful regional lymphadenopathy. In some cases, kerions or boggy tumours studded with pustules may develop which may be misdiagnosed as bacterial abscesses. A generalised eruption of small itchy papules particularly around the outer helix of the ear, although it can occur anywhere, can occur as a reactive phenomenon or ‘id’ response (Higgins et al., 2000; González et al., 2007).

Fungus can either penetrate the hair shaft (endothrix infection) or penetrate the hair shaft and grow over the outside of the hair shaft at the same time (exothrix infection). Some other conditions can be confused with tinea capitis (Health Protection Agency, 2007). In alopecia areata, there is rarely inflammation in the area of alopecia and no scaling or itching. Seborrhoeic dermatitis occurs in children of all ages but the scaling is diffuse and there is seldom associated hair loss. Scalp psoriasis produces more scaling.

The pattern of tinea capitis has changed in the UK over the past 10 years (Health Protection Agency, 2007) with a significant rise in the incidence and prevalence of causes of infection due to the anthrophilic organism, Trichophyton tonsurans (T. tonsurans), which causes endothrix infection. The main focus of the infection has historically been linked to Afro Caribbean communities and therefore cities where there are long standing or recently established black communities but the Health Protection Agency (2007) makes it clear that infection can occur in any child irrespective of their ethnic origin. Indeed Higgins et al. (2000) recommend that as it is now so widespread it should be considered in the diagnosis of any child over 3 months with a scaly scalp.

Laboratory diagnosis
Specimens should be taken whenever possible to confirm the diagnosis as systemic therapy will be required. Skin scrapings (Box 12.3) or brushings which include hair and hair fragments (Box 12.4) should be used and sent for mycology. Cut hair is not helpful because of the endothrix nature of the infection; hairs should be plucked. Culturing of the scrapings allows for accurate identification of the organism. These should be repeated after treatment to determine whether the treatment has been effective or not. The use of Wood’s light examination is not usually helpful as T. tonsurans is an endothrix infection so does not fluoresce.

Box 12.3 Skin scraping sample Hold a blunt blade at an angle of 45 degrees; Scrape along the active scaly edge of the lesion without cutting the patient; Wipe the blade edge or catch the keratin scale onto the black filter paper container.     Source: RCN/BDNG (2008).

Box 12.4 Hair debris Identify affected hair follicles and remove skin, hair and/or debris for collection suing a firm toothbrush. Fold inside the black filter paper container.     Source: RCN/BDNG (2008).

Management

1. Treatment must be systemic. Most superficial fungal infections can be treated topically. However tinea capitis (like fungal nail infections) always requires systemic medication (González, 2007) as the infection is found at the root of the hair follicle which cannot be reached by topical agents.
2. Incision and drainage of kerions is not helpful and must be avoided.
3. Removal of surface crusts from a kerion is often helpful as it relieves itching and secondary infection. It can be painful but can be done gently after soaking the kerion with lukewarm water or saline (Health Protection Agency, 2007).
4. Griseofulvin remains the only licensed treatment for scalp ringworm in the UK. Absorption is improved if taken with fatty foods. The dose is at least 10 mg/kg per day for 6–8 weeks but up to 20 mg/kg may be required (Higgins et al., 2000).
5. Terbinafine is now well documented for treatment at doses based on weight: <20 kg, 62.5 mg/day; 20–40 kg, 125 mg/day and 40 kg, 250 mg/day for 4 weeks. Terbinafine tablets only are available. The newer treatments (Terbenafine, Itraconazole) are similar to Griseofulvin and may be preferred because the treatment durations are shorter and all have reasonable safety profiles (González et al., 2007). However, they are not licensed for use in the UK and are not all available in paediatric suspensions (Health Protection Agency, 2007).
6. The use of a topical treatment, for example selenium sulphide or ketaconazole shampoo, or another topically active antifungal, for example Terbenafine cream, is recommended for the first 2 weeks of therapy as this may allow the scalp to heal and prevent formation of crusts where there are kerions (Health Protection Agency, 2007). Carriers should also be given a topical preparation.
7. Hairbrushes and combs should be cleaned with simple bleach or Milton (Higgins et al., 2000).
   
   

Parents are often horrified that their child has a fungal infection and need reassurance that this is not due to a worm (Broomhead, 2007). Children do not need to be kept off school (Health Protection Agency, 2007) as although theoretically there is a potential risk to noninfected children; the method of spread is not clear and the infected child is likely to have been at school for sometime before detection of the infection. Exclusion is probably too late to prevent spread and in addition only reinforces a child’s isolation.

Other children in the household should also be examined. Adults in contact with tinea capitis can very rarely develop tinea corporis.