Ringworm (Tinea): Fungal Infection Causes Intense Itching and Circular Rash

Tinea (dermatophytosis), commonly called ringworm, is a superficial fungal infection of keratinized tissues (skin, hair, nails) caused by dermatophytes (Trichophyton, Microsporum, Epidermophyton).

Clinical Presentation

• Annular plaques: Red, scaly, raised borders with central clearing — "ring" appearance.
• Intense pruritus (itching): Hallmark symptom; can be severe, disrupting sleep.
• Location-specific names:
  • Tinea corporis (body)
  • Tinea cruris (groin — "jock itch")
  • Tinea pedis (feet — "athlete's foot")
  • Tinea capitis (scalp — mostly children)
  • Tinea unguium/onychomycosis (nails)
  • Tinea barbae (beard)
  • Tinea manuum (hands)
  • Tinea faciei (face)

Transmission

• Direct contact (human, animal — especially kittens/puppies)
• Fomites (towels, clothing, combs, gym mats)
• Soil (geophilic species)

Risk Factors

• Occlusive clothing, hyperhidrosis
• Immunosuppression, diabetes
• Contact sports, communal showers
• Pet ownership

Diagnosis

• Clinical appearance
• KOH preparation (hyphae visualization)
• Fungal culture (species ID)
• PCR (rapid, sensitive)
• Wood's lamp (some Microsporum fluoresce green)

Treatment

• Topical antifungals (terbinafine, clotrimazole, miconazole, ketoconazole) × 2–4 weeks for limited skin disease.
• Oral antifungals (terbinafine, itraconazole, fluconazole, griseofulvin) for extensive, hair/nail involvement, or topical failure.
• Adjuvant: Antihistamines for itch; topical steroids only if combined with antifungal (avoid monotherapy — "tinea incognito").

Prevention

Keep skin dry, avoid sharing personal items, treat infected pets, wear footwear in communal areas.