Clinical Features:

• Common cutaneous or ungual infection caused by members of three genera of fungi: Epidermophyton, Microsporum and Trichophyton.
• Clinically named according to the site of infection:
  • Tinea capitis: Infection of the scalp.  Varies from mild erythema to inflammatory lesions with pustules and folliculitis
  • Tinea corporis: Infection of glaborous skin.  Also known as "ringworm."  Presents as an erythematous, centrifugally growing annular lesion with a peripheral scale.
  • Tinea barbae: Infection of the beard area
  • Tinea cruris: Infection of the inguinal area.  Also known as "jock itch."  Almost exclusively seen in males.
  • Tinea pedis: Infection of the foot.  Also known as "athlete's foot."  There are three types: plantar moccasin-like, interdigital and vesiculobullous.
  • Tinea manuum: Infection of the hand.  Often coexists with tinea pedis.  Most often presents as hyperkeratosis with prominent flexural creases.
  • Tinea unguium: Infection of the nails.  Also known as onychomycosis. 

Histologic Features:

• The histologic findings are highly variable.
• Epidermal changes may include:
  • Neutrophilic infiltrate
  • Compact orthokeratosis
  • "Sandwich sign": hyphae "sandwiched" between an upper normal-appearing stratum corneum and a lower layer of compact orthokeratosis or parakeratosis
  • Mild spongiosis (Significant spongiosis and vesiculation may be present on acral skin.)
  • Acanthosis in chronic lesions
• Dermal changes may include:
  • Mild superficial edema
  • A mild to moderate perivascular infiltrate of lymphocytes and occasional neutrophils and eosinophils
• Fungal forms in the form of yeasts and bizarre hyphae are best appreciated on PAS or GMS stains. 

Cases associated with this book:

Dermatophytosis
Author: Artur Zembowicz M.D. Ph.D.

Conference: DermatopathologyConsultations.com Teaching Collection