💅 Ringworm (Tinea Corporis) Contagion & Treatment Simulator

Contact With An Infected Source

Ringworm spreads through direct contact with contaminated skin, fur, or surfaces.

• High: Person-to-person risk (skin-to-skin contact)
• Moderate: Zoonotic risk (pets, livestock)
• Weeks: Fomite survival (on surfaces)
• 4–14 d: Incubation period (before rash appears)

Human contact

Wrestling, shared bedding, and skin contact spread spores between people.

Animal contact

Cats, dogs, and livestock often carry dermatophytes without visible symptoms.

Surface contact

Gym mats, towels, and combs harbor infectious spores for weeks.

Spores Land On New Skin

Microscopic fungal spores attach to the outer keratin layer of fresh skin.

• 2–5 µm: Spore size (microscopic arthrospores)
• Minutes: Adherence time (to attach to keratin)
• Warm/moist: Ideal conditions (sweat, occlusion)
• Yes: Minor trauma needed (micro-abrasions help entry)

Keratin affinity

Dermatophytes uniquely digest keratin, the protein of skin, hair, and nails.

Moisture and friction

Sweaty, occluded skin areas favor spore germination and hyphal growth.

Barrier breach

Tiny scratches or abrasions let spores penetrate the stratum corneum.

The Ring-Shaped Rash Forms

Fungal hyphae grow radially outward, creating the characteristic annular lesion.

• Centrifugal: Growth pattern (outward from origin)
• 1–5 cm: Ring diameter (typical untreated size)
• Common: Central clearing (active border, clear center)
• Mild–mod: Itch severity (pruritic border)

Active border

The advancing edge is scaly, red, and where live fungus concentrates.

Central clearing

Older central skin heals as the fungus advances outward only.

Multiple lesions

Repeated contact can seed several rings across the body.

Antifungal Cream Application

Daily topical antifungals halt fungal growth at the active rash border.

• Azoles: First-line agents (clotrimazole, terbinafine)
• 1–2×/day: Application freq (beyond rash edge)
• 2–4 wk: Typical course (topical therapy)
• >80%: Cure rate (uncomplicated cases)

Mechanism

Azoles and allylamines disrupt fungal cell membrane synthesis directly.

Application area

Cream must extend past the visible border to catch spreading hyphae.

Adherence matters

Stopping early after symptoms fade risks relapse and regrowth.

Rash Resolves Over Weeks

Consistent treatment shrinks the ring until skin returns to normal.

• 1–2 wk: Visible improvement (reduced redness)
• 4–6 wk: Full clearance (typical timeline)
• Low: Recurrence risk (if course completed)
• Drops fast: Contagion after Rx (within days of therapy)

Shrinking ring

The active border retreats inward week by week under treatment.

Reduced contagion

Treated lesions shed far fewer viable spores to others.

Preventing recurrence

Treating pets, disinfecting items, and finishing the course prevent relapse.