Fungus

Tinea Capitis

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Tinea Capitis

  • See Also
  1. Scalp Dermatitis
  • Epidemiology
  1. Children most often affected (esp. ages 4-14 years)
  • Risk Factors
  1. Household exposure
  2. Low socioeconomic groups
  • Causes
  1. Trichophyton tonsurans (90-95% of U.S. cases)
  2. Microsporum species from dogs and cats (fluoresce blue-green under wood's lamp)
    1. Microsporum canis
    2. Microsporum audouinii
  • Pathophysiology
  • Contagious Spread
  1. Easily spread by fomites or hair
    1. Contaminated hats, brushes or barber instruments
    2. Infectious fungal particles are viable on fomites for months
  2. Person to Person Spread
    1. Non-Inflammatory Tinea Capitis
    2. Black dot Ringworm
  3. Spread from cats, dogs, and soil
    1. Inflammatory Tinea Capitis
  • Differential Diagnosis
  1. Scaling and Inflammation predominant
    1. Seborrheic Dermatitis
    2. Atopic Dermatitis
    3. Psoriasis
    4. Impetigo
    5. Cellulitis
  2. Alopecia predominant
    1. Discoid Lupus
    2. Syphilis
    3. Alopecia Areata
    4. Trichotillomania
    5. Traction Alopecia
  • Symptoms
  1. Pruritus (especially in Inflammatory Tinea Capitis)
  • Signs
  1. General findings
    1. Circumscribed areas of Alopecia
    2. Boggy, raised lesion
      1. Rim of erythema (variable)
      2. Fine scale
    3. Microsporum lesions fluoresce under Wood's Lamp
      1. Trichophyton (92% of cases) does not fluoresce
      2. Hence most cases of Tinea Capitis do not fluoresce
  2. Classic presentation strongly suggests Tinea Capitis
    1. Pruritus
    2. Posterior Cervical Lymphadenopathy (absent in Alopecia)
    3. Alopecia
    4. Scaling
    5. Hubbard (1999) Arch Pediatr Adolesc Med 153(11): 1150-3 [PubMed]
  3. Non-inflammatory (epidemic) Tinea Capitis
    1. Hair gray or lusterless
    2. Hair breaks above scalp
    3. Wood's Lamp: Fluorescent (Microsporum species)
  4. Inflammatory Tinea Capitis
    1. Scalp red with Pustules or with painful, red, boggy Plaque (kerion)
      1. Psoriasis appearance, but hairs are broken off
      2. Purulent drainage
    2. Fever
    3. Posterior Cervical Lymphadenopathy
    4. Wood's Lamp: Fluorescent (Microsporum species)
  5. Black dot Ringworm
    1. Hair breaks off at skin level
      1. Scalp studded with tiny black dots
    2. Wood's Lamp: Not Fluorescent
  • Diagnosis
  • Criteria for empiric treatment
  1. Criteria: Three or more of the following present
    1. Scalp Scaling
    2. Alopecia
    3. Occipital adenopathy
    4. Scalp Pruritus
  2. Interpretation
    1. Findings highly suggestive of Tinea Capitis in child
    2. Test Sensitivity: 92% (but small study)
    3. Justifies empiric Tinea Capitis therapy
  3. References
    1. Hubbard (1999) Arch Pediatr Adolesc Med 153:1150-3 [PubMed]
  • Complications
  • Kerion
  1. Allergic sensitization to fungus
  2. Results in Alopecia if untreated
  • Labs
  1. Potassium Hydroxide (KOH)
    1. Sample active border of inflamed patch
  2. Hair Fungal Culture
    1. Typically requires 6 weeks for results
  • Management
  1. General
    1. Examine household contacts (and treat if Tinea Capitis present)
    2. Most Antifungal Medications require lab monitoring
      1. See specific agents for details
    3. Confirm the diagnosis first with Potassium Hydroxide (KOH) preparation and Fungal Culture
      1. Kerion treatment should be started immediately while awaiting culture results
      2. Children with classic findings (e.g. Pruritus, Scaling, Alopecia, adenopathy) may be treated empirically
  2. First Line: Terbinafine
    1. Adult (and child >40 kg): 250 mg orally daily for 2-4 weeks
    2. Child 20-40 kg: 125 mg (up to 187.5 mg) orally daily for 2 weeks
    3. Child <20 kg: 62.5 mg (up to 125 mg) orally daily for 2 weeks
    4. Trichophyton tonsurans may require 2-4 weeks of treatment
    5. Microsporum canis may require 4-8 weeks of treatment
  3. Alternative Agents
    1. Fluconazole
      1. Daily: 6 mg/kg (up to 150 mg) daily for 3-6 weeks
      2. Weekly: 6 mg/kg (up to 150 mg) each week for 8-12 weeks
    2. Itraconazole
      1. Daily
        1. Solution 3 mg/kg/day up to 500 mg/day for 4-6 weeks
        2. Capsules 5 mg/kg/day up to 500 mg/day for 4-6 weeks
      2. Monthly
        1. Solution 3 mg/kg/day up to 500 mg/day, daily for one week per month for 2-3 months
        2. Capsules 5 mg/kg/day up to 500 mg/day, daily for one week per month for 2-3 months
    3. Griseofulvin
      1. Less effective for Trichophyton tonsurans (accounts for most cases of U.S. Tinea Capitis)
      2. May be more effective for microsporum species
      3. Griseofulvin microsize (Griseofulvin V)
        1. Adult: 500 mg (up to 1 g) orally daily
        2. Child: 20 to 25 mg/kg/day (max 1000 mg/day, AAP dosing) orally daily until Hair Growth (typically 8 weeks)
      4. GriseofulvinUltramicrosize (more expensive, but may have better absorption)
        1. Adult: 375 mg orally once daily (up to twice daily)
        2. Child: 10 to 15 mg/kg orally daily (max 750 mg/day, AAP off-label dosing)
  4. Concurrent Topical Antifungal reduces transmission
    1. May also be used in asymptomatic household contacts
    2. Apply for 5 minutes 2-3 times each week
    3. Agents
      1. Selenium Sulfate (2.5%) or
      2. Topical Ketoconazole or
      3. Povidone Iodine lotion or Shampoo
  5. Kerion
    1. Antifungal agent AND
    2. Corticosteroid
      1. Prednisone 1 mg/kg/day or
      2. Topical Triamcinolone 0.1% Cream
  • References
  1. Gilbert (2013) Sanford Guide to Antimicrobials
  2. Andrews (2008) Am Fam Physician 77(10): 1415-20 [PubMed]
  3. Ely (2014) Am Fam Physician 90(10): 702-10 [PubMed]
  4. Schwartz (2004) Lancet 364(9440):1173-82 [PubMed]
  5. Nesbitt (2000) Int J Dermatol 39(4):261-2 [PubMed]