4-50
be grouped into 3 main categories: from animals, from the environment, and from one another. Infections
are seen worldwide.
Subjective: Symptoms
Rash, itching and flaking; severe cases: Painful, pruritic blisters.
Objective: Signs
Using Basic Tools:
Tinea corporis: Scaling, sharply demarcated plaque (with or without vesicles or pustules) with central
clearing and peripheral enlargement producing an annular configuration, commonly on forearm and neck.
(see Color Plates Picture 2)
Tinea pedis: Various patterns: Slightly erythematous plague on the plantar surface of the foot; dry,
superficial, white scale is observed in an arciform pattern; moist patch of erythema, small fissures and
erosions usually localized to the third and fourth interdigital spaces and the lateral sole.
Tinea unguium (onychomycosis): Whitish/yellow/brown, thick, dry, subungual (under nail) accumulation of
friable keratin debris; the great toe is commonly affected first. (see Color Plates Picture 1)
Tinea capitis: 3 main groups: Focal patch of alopecia with minimal scale and erythema; “Black dot”
appearance of broken of hair shafts also seen with minimal scale and erythema; kerion- a boggy, purulent,
inflamed group of pustules that is often tender to touch and heals with severe scarring.
Tinea cruris: Similar to Tinea corporis but restricted to the intertriginous area of the groin.
Tinea barbae: Similar to Tinea corporis but restricted to the facial area.
Tinea manuum: Similar to Tinea corporis but restricted to the hands and feet.
Using Advanced Tools: Lab: KOH preparation for characteristic fungal hyphae.
Assessment:
Differential Diagnosis
Pityriasis rosea, discoid eczema, and psoriasis. See appropriate sections and index in this book. Diagnosis
requires a KOH preparation (see Color Plates Picture 3 and Lab Procedures).
Plan:
Treatment
Primary: Lac-Hydrin and Clotrimazole topically bid for 2-4 weeks for tinea pedis and onychomycosis.
Lac-Hydrin decreases the dryness and increases the barrier properties of the skin.
Griseofulvin 500 mg bid with fatty meals (aids absorption) for 2 weeks for tinea corporis to 2 to 3 months for
tinea capitis. Not effective against candidiasis or tinea versicolor.
Clotrimazole topical preparations (cream and solution) are effective against most fungal infections when
applied bid/tid to affected areas and washed off before reapplication.
Alternate: Itraconazole and terbinafine are not recommended in the field due to the inability to properly
evaluate side effects. A more effective treatment of onychomycosis is prevention and topical ciclopirox
nail lacquer (Penlac).
Note: Nystatin treats only candidal infections not dermatophytes
Patient Education
Prevention and Hygiene: Good foot maintenance: change socks frequently, dry out boots, use antifungal
soaps, use shower shoes.
Follow-Up Actions:
Reevaluation: Repeat KOH evaluation and clinical assessment.
Evacuation/Consultation Criteria: Evacuation should not be necessary. Consult for difficult cases.
Zoonotic Disease Considerations
Dermatophytosis (Ringworm)