Tinea Capitis

Aka: Tinea Capitis

advertisement

II. Epidemiology

  1. Children most often affected (esp. ages 4 to 14 years)
  2. More common in black children (esp. ages 3 to 9 years old)

III. Risk Factors

  1. Household exposure
  2. Low socioeconomic groups

IV. 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

V. 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

VI. 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

VII. Symptoms

  1. Pruritus (especially in Inflammatory Tinea Capitis)

VIII. Signs: General

  1. Characteristics
    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]

IX. Signs: Sub-Types

  1. Black dot Ringworm (Trichophyton, 89% of cases in U.S.)
    1. Hair breaks off at skin level
      1. Scalp studded with tiny black dots
    2. Wood's Lamp: Not Fluorescent
  2. Non-inflammatory (epidemic) Tinea Capitis (gray patch, Microsporum)
    1. Hair gray or lusterless
    2. Hair breaks above scalp
    3. Wood's Lamp: Fluorescent (Microsporum species)
    4. More common in South America, Europe, Africa and Middle East
  3. Inflammatory Tinea Capitis (favus)
    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)

X. 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]

XI. Complications: Kerion

  1. Allergic sensitization to Fungus, results in boggy, tender Plaques and Pustules
  2. Results in Alopecia if untreated

XII. Labs

  1. Potassium Hydroxide (KOH)
    1. Test Sensitivity: 51 to 97%
    2. Sample active border of inflamed patch
    3. Scrapings of black dots (broken hairs) may also yield fungal spores
  2. Hair Fungal Culture
    1. Test Sensitivity: 51 to 97%
    2. Sample with a moistened cotton swab (or ToothBrush) rubbed over the scalp lesion
    3. Collected in Sabouraud liquid medium or dermatophyte test medium
    4. Typically requires 6 weeks for results
    5. High False Negative Rates in children, and with kerion

XIII. 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. Preferred for black dot Tinea Capitis (Trichophyton), representing 89% of cases in U.S.
    2. Adult (and child >40 kg): 250 mg orally daily for 2-4 weeks
    3. Child 20-40 kg: 125 mg (up to 187.5 mg) orally daily for 2 weeks
    4. Child <20 kg: 62.5 mg (up to 125 mg) orally daily for 2 weeks
    5. Trichophyton tonsurans may require 2-4 weeks of treatment
    6. Microsporum canis may require 4-8 weeks of treatment (or switch to Griseofulvin)
  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, esp. black dot tinea)
      2. May be more effective for microsporum species (gray patch tinea)
      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 sulfide (1 to 2.5%) or
      2. Topical Ketoconazole 2% or
      3. Ciclopirox 1.5%
      4. 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

XIV. References

  1. Gilbert (2013) Sanford Guide to Antimicrobials
  2. Andrews (2008) Am Fam Physician 77(10): 1415-20 [PubMed]
  3. Caplan (2025) Am Fam Physician 112(4): 382-92 [PubMed]
  4. Ely (2014) Am Fam Physician 90(10): 702-10 [PubMed]
  5. Schwartz (2004) Lancet 364(9440):1173-82 [PubMed]
  6. Nesbitt (2000) Int J Dermatol 39(4):261-2 [PubMed]

Images: Related links to external sites (from Bing)

These images are a random sampling from a Bing search on the term "Tinea Capitis." Click on the image (or right click) to open the source website in a new browser window. Search Bing for all related images

Related Topics in Fungal Infections

advertisement