Tinea Infections and Treatment

Tinea Infections

• Tinea incognito: a type of fungal infection that can be misdiagnosed due to its non-classical presentation
• Tinea barbae: a ringworm infection that affects the beard, mainly in adults in contact with farm animals
  • Lesions may present as kerion or tinea circinata, mostly unilateral
  • Treatment: oral and topical antifungals
• Tinea cruris: a ringworm infection that affects the groin, mostly in men on upper and inner surfaces of the thighs
  • Clinical picture: small erythematous, scaly patch that spreads peripherally and partly clears in the center, edge is well defined with papules, vesicles or pustules
  • Itching is common
  • Differential diagnosis: erythrasma, seborrheic dermatitis, flexural psoriasis, simple intertrigo, candidal intertrigo, and streptococcal intertrigo
  • Treatment: drying the lesions, specific topical and oral antifungals
• Tinea pedis: a ringworm infection that affects the feet, also known as athlete's foot
  • Most common fungal infection, more common in adult males
  • Predisposing factors: wearing tight shoes, communal showers, swimming baths, and hyperhydrosis
  • Clinical varieties: interdigital, squamous hyperkeratotic, and vesiculobullous
  • Patient may complain of itching, bad smell, or secondary bacterial infection

Fungal Infections

• Fungal infections can be divided into superficial or deep (systemic) infections
• Superficial infections are restricted to skin and its appendages, while deep infections are usually of systemic nature with occasional involvement of skin
• Fungal infections can be caused by:
  • Dermatophytes: cause superficial infections, classified into microsporum, trichophyton, and epidermophyton
  • Yeasts: e.g. malassezia furfur (causes pityriasis versicolor) and candida albicans

Dermatophyte Infections

• Clinical types of dermatophyte infections:
  • Tinea capitis (ringworm of the scalp)
  • Tinea corporis (tinea circinata)
  • Tinea barbae (ringworm of the beard)
  • Tinea cruris (ringworm of the groin)
  • Tinea pedis (ringworm of the feet)
  • Onychomycosis (fungal infection of the nails)

Tinea Capitis

• Mainly affects school children, more common in boys than girls
• Main causative fungi in Egypt: trichophyton violaceum and microsporum canis
• Clinical picture:
  • Scaly type: single or multiple scaly patches, often circular in shape, with numerous broken-off hairs
  • Kerion (inflammatory type): caused by animal fungi, presented as boggy indurated swellings with crusting and loose hairs
  • Black-dot type: bald patches with formation of black dots as the affected hair breaks at the surface of the scalp
  • Favus: caused by trichophyton schoenleinii, characterized by yellowish, cup-shaped crusts (scutula) with a distinctive mousy odor
• Modes of infection: direct contact with infected child, indirect through use of patient's fomites
• Diagnosis: clinical, Wood's light examination, direct microscopic examination, and culture
• Treatment: topical and systemic antifungals