Tinea Capitis

Tinea capitis is one the most common fungal diseases in children. 

Epidemiology

  1. The organism causing the majority of cases of T. capitis has changed from Microsporum canis and Microsporum audouinii to Trichophyton tonsurans (90%) in recent years.
  2. Age range of disease is from neonates to adults although the highest incidence is in 3-9 year olds
  3. Transmission is from person to person and children and adults may be asymptomatic carriers. The fungi can live on combs, couches, and sheets for long periods of time
  4. The incubation period is unknown
  5. There is a marked greater incidence in African Americans compared to Caucasians and Hispanics and the incidence in Asians is low
Pathophysiology
      1. Organism are often supeficial colonizers of the skin but can invade the underlying layers
      2.  May invade the hair follicle and have resultant broken hairs.

Clinical Presentation
  1. Classical presentation is alopecia, scales, and erythema. The borders may be slightly raised. There may be evidence of broken hairs.
  2. May present with scaling and minimal or no evidence of hair loss. Often resembles seborrhea dermatitis. Often diffuse and some pruritus. 
  3. May have presentation that appears to be a folliculitis or impetiginous lesions. There may be pustules. crusting and scaling. Very common in African Americans
  4. Kerions. These are inflammatory lesions found on the scalp that are boggy, tender, pustular, and red. These are thought to be hypersensitivity reactions to the fungus.
  5. May also have a confluent morbilliform pruritic rash (id reaction).
Differential Diagnosis
  1. Seborrhea- usually in children <6 months old. Not pruritic.
  2. Atopic dermatitis
  3. Trichotillomania and tight braiding
  4. Psoriasis
  5. Impetigo and folliculitis
  6. Alopecia areata- usually there is no scaling or erythema
Diagnosis
  1. Clinical picture and exposure usually makes the diagnosis
  2. KOH preparation may verify presence of fungus
  3. Culture on special media- Sabouraud's or DTM. Rubbing toothbrush across the scalp 10 times may be an effective way to get scales and debris for culture.  May take 1-2 weeks to grow
  4. T. tonsurans is not fluorescent so Wood's lamp will miss 90% of cases.
Treatment
  1. Griseofulvin. 15-25 mg./kg per day for 6-8 weeks. Maximum of 1 gram. Should take after fatty meal to enhance absorption. Side effects include nausea, vomiting, photosensitivity, leukopenia, anemia, and LFT changes. Should do laboratory evaluation if symptoms develop.
  2. Ketoconazole (Nizoral) is the second choice for treatment if unable to tolerate Griseofulvin.
  3. Kerions- if symptomatic, 1mg/kg/day of po Prednisone for 5-10 days
  4. Selenium Sulfide 2.5% shampoo to kill spores and decrease spread. May use in other household members without symptoms.
  5. The child may return to school during treatment and it is not necessary to wear hats or shave head.
  6. Newer dugs being evaluated include Terbinafine(Lamisil), fluconazole(Diflucan), and itraconazole(Sporanox)
References
  1. Elewski BE. Tinea Capitis: A Current Perspective. Journal of the American Academy of Dermatology. 2000; 42(1):1-20.
  2. Friedlander SF et al. Use of the Cotton Swab Method in Diagnosing Tinea Capitis. Pediatrics. 1999; 104(2):276-279.
  3. Smith, Michael. Tinea Capitis. Annals of Pediatrics. Feb. 1996.
  4. Stein DH. Tineas - Superficial Dematophyte Infections. Pediatrics in Review. 1998; 19:368-372.
  5. Friedlander S.F. et al. Terbinafine in the Treatment of TrichophytonTinea Capitis. Pediatrics Vol 109 No. 4  page 602. April 2002
  6. Fleece D. Griseofulvin Versus Terbinafine in the Treatment of Tinea Capitis: A Meta-analysis of Randomized Clinical Trials.  Peidatrics November 2004
  7. Shy R. Tinea Corporis and Tinea Capitis. Pediatrics in Review May 2007