🦷 Athlete's Foot (Tinea Pedis) Antifungal Treatment Simulator

Healthy Foot Skin

Intact stratum corneum, dry interdigital spaces, no pathogens present.

• ~5.0: Interdigital pH (acid mantle intact)
• Low: Skin moisture (dry toe web)
• 0%: Fungal burden (no colonization)
• 100%: Barrier integrity (unbroken stratum corneum)

Foot skin anatomy

Thick stratum corneum, thin web spaces, keratin barrier.

Normal microflora

Resident bacteria and yeast, low-level, non-pathogenic.

Barrier defenses

Acid mantle, sebum, desquamation limit colonization.

Dermatophyte Exposure

Warm, moist shared surfaces transfer spores to interdigital skin.

• Locker rooms: Common source (shared showers, mats)
• T. rubrum: Primary organism (most frequent species)
• ~12%: Fungal burden (early colonization)
• 1–3 wks: Incubation (to visible symptoms)

Spore transmission

Arthrospores survive on damp floors for weeks.

Risk environment

Occlusive shoes, sweat, warmth favor colonization.

Interdigital preference

4th web space is narrowest, most humid site.

Fungal Growth & Symptoms

Hyphae invade keratin, producing scale, itch, and maceration.

• ~68%: Fungal burden (progressing infection)
• Itch: Symptom onset (plus scaling, fissuring)
• Macerated: Web space (white, softened skin)
• Active: Keratinase (digests keratin for nutrients)

Hyphal invasion

Branching filaments spread laterally through keratin.

Inflammatory response

Itching, erythema, and fissuring develop.

Maceration risk

Moisture trapping softens skin, aids penetration.

Topical Antifungal Applied

Terbinafine kills hyphae directly; clotrimazole halts their growth.

• Fungicidal: Terbinafine (kills fungal cells)
• Fungistatic: Clotrimazole (halts fungal growth)
• Ergosterol: Mechanism (membrane synthesis blocked)
• ~86%: Peak burden (at treatment start)

Terbinafine mechanism

Blocks squalene epoxidase, ruptures fungal membrane.

Clotrimazole mechanism

Blocks ergosterol synthesis, stalls fungal growth.

Application routine

Applied to clean, dry interdigital skin daily.

Clearance Over the Treatment Course

Fungal burden declines; terbinafine clears faster than clotrimazole.

• 1–2 wks: Terbinafine course (typical clearance)
• ~4 wks: Clotrimazole course (needs longer course)
• <1%: Terbinafine day 14 (burden remaining)
• ~26%: Clotrimazole day 14 (burden remaining)

Fungicidal clearance

Rapid hyphal death, short course, low relapse.

Fungistatic clearance

Slow immune-driven clearance, longer course needed.

Immune dependence

Clotrimazole relies on intact host immune clearance.