Dermatology Book

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Tinea CorporisAka: Tinea Circinata, Ringworm

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  1. Etiology
    1. Trichophyton rubrum
    2. Trichophyton tonsurans
    3. Trichophyton mentagrophytes
    4. Microsporum canis
    5. Epidermophyton floccosum
  2. Pathophysiology
    1. Infection
      1. Exposure to contaminated soil
      2. Exposure to infected animals or people
    2. Growth and transmission facilitating factors
      1. Warm and moist environments (showers and pools)
      2. Shared towels or clothing
  3. Signs
    1. Location: Glabrous skin (excludes palms, soles, groin)
    2. Characteristics
      1. Round, erythematous, Scaling, pruritic Plaques
      2. Annular Lesion (hence the name ringworm)
        1. Raised, advancing border
        2. Plaque with central clearing
          1. No central clearing after Corticosteroid use
      3. Postinflammatory pigmentation changes
  4. Precautions
    1. Widespread ringworm suggests underlying disease
  5. Lab
    1. Potassium Hydroxide (KOH 20%)
      1. Scrape from active border
    2. Chlorazol black
      1. Highlights fungal hyphae
    3. Fungal Culture
      1. Suspected dermatophyte infection despite negative KOH
      2. Dermatophyte testing medium (DTM)
    4. Biopsy
      1. PAS stain will show hyphae in Stratum Corneum
  6. Differential Diagnosis
    1. See Annular Lesion
    2. Pityriasis Rosea (Herald patch)
    3. Nummular eczema
    4. Drug allergy
    5. Psoriasis
    6. Contact Dermatitis
    7. Discoid Lupus
    8. Bowen's Disease
    9. Parapsoriasis
    10. Mycosis Fungoides (Cutaneous T Cell Lymphoma)
    11. Granuloma Annulare
  7. Management
    1. Prevent re-infection (see pathophysiology above)
    2. Topical Antifungal applied twice daily for 2-3 weeks
      1. Technique
        1. Apply to normal skin 2 cm beyond affected area
        2. Continue for 7 days after symptom resolution
      2. First line: Imidazoles (e.g. Clotrimazole)
      3. Refractory cases: Allylamines (e.g. Naftin, Lamisil)
    3. Systemic Antifungal
      1. Indications
        1. Immunocompromised patient
        2. Disabling or widespread lesions
        3. Chronic infection
        4. Hyperkeratotic area involvement (palms or soles)
      2. Preparations
        1. Terbinafine 250 mg PO qd for 2 weeks
        2. Fluconazole 150 mg PO once per week for 1-4 weeks
        3. Itraconazole (Sporanox)
        4. Griseofulvin 0.5-1.0 grams per day
        5. Ketoconazole 200 mg PO qd for 4 weeks
          1. No recommended due to potential hepatic injury
  8. Complications
    1. Deep follicular tinea infection (Majocchi's Granuloma)
      1. Complication of Topical Corticosteroid use
      2. More commonly affects women, and most often on legs
  9. References
    1. Gilbert (1999) Sanford Guide to Antimicrobials
    2. Drake (1996) J Am Acad Dermatol 34(2 pt 1):282
    3. Hsu (2001) Am Fam Physician 64(2):289

Tinea (C0040247)

Definition (MSH)A general term describing various dermatophytoses. Specific types include TINEA CAPITIS (ringworm of the scalp), TINEA FAVOSA (of scalp and skin), TINEA PEDIS (athlete's foot), and tinea unguium (see ONYCHOMYCOSIS, ringworm of the nails). (Dorland, 27th ed)
Definition (CSP)general term describing various dermatophytoses; specific types include tinea capitis (ringworm of the scalp), tinea favosa (of scalp and skin), tinea pedis (athlete's foot), and tinea unguium (ringworm of the nails).
ConceptsDisease or Syndrome (T047)
ICD9110.9
EnglishMicrosporic tinea, ringworm, Tinea, Tinea Infections, Tineas
Spanishsérpigo, serpigo, tiña, tiña microspórica, tina, tina microsporica
CreditsDerived from the NIH UMLS (Unified Medical Language System)



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