Tinea Infections Health Article

Description

• Dermatophytic fungal infection that typically affects the skin, hair, or nails, with each region affected having specific inflammatory patterns.
• Characterized by superficial inflammation within marked margins, dry, scaly skin, and hair loss; often misdiagnosed as psoriasis, impetigo, seborrhea, eczema, and other skin conditions.
• Difficult to achieve total symptom relief; often recurrent.
• Usually treated with topical antifungals, but systemic antifungal agents may be necessary.

Synonyms

• Ringworm.
• Athlete's foot (tinea pedis).
• Jock itch (tinea cruris).
• Onychomycosis (tinea unguium).

Background

Cardinal features

• Superficial fungal infection commonly affecting the groin (tinea cruris), feet (tinea pedis), hands (tinea manuum), nails (onychomycosis), scalp (tinea capitis), trunk and extremities (tinea corporis), face (tinea faciei), facial hair (typically beards; tinea barbae), and causing variably colored scaly patches on the chest, back, or shoulders (tinea versicolor).
• Scaly, erythematous lesions with marked borders in specific body areas with moist dark environments that promote friction.
• Approx. 10-20% of people are infected, males more than females; commonly affects adolescents and adults more than children.
• Sources of infection include soil, contaminated surfaces and articles, animals, and human contact.

Causes

Common causes.

Tinea infections are caused by dermatophytes:

• Tinea cruris: Trichophyton rubrum, T. mentagrophytes, Epidermophyton floccosum, Candida albicans .
• Tinea pedis: T. rubrum, T. mentagrophytes, T. tonsurans, T. verrucosum, Microsporum canis, M. gypseum, E. floccosum .
• Tinea manuum: T. rubrum, T. mentagrophytes, Trichophyton spp., Epidermophyton spp., Microsporum spp.
• Tinea capitis: T. tonsurans in the US, Africa; T. schoenleinii in Africa; M. canis in the UK, South America, and Saudi Arabia; T. megninii in Portugal; T. tonsurans and T. violaceum are associated with black dot ringworm; M. canis, T. mentagrophytes, and T. verrucosum are associated with kerion; M. audouinii is associated with gray patch ringworm.
• Tinea corporis: T. tonsurans, T. verrucosum; T. rubrum causes Majocchi's granuloma.
• Tinea barbae: T. mentagrophytes, T. verrucosum .
• Tinea versicolor: Malassezia furfur .

Rare causes

Trichosporon spp., Fusarium spp., Aspergillus spp., Scopulariopsis spp., Piedraia spp., and Scytalidium spp.

Serious causes

Chronic mucocutaneous candidiasis may present with superficial skin infection associated with polyendocrine deficiency, neutrophil defects, immune suppression.

Contributory or predisposing factors

• Tinea cruris: warm, moist conditions; heavy sweating; wet clothing; layered clothes.
• Tinea pedis: warm, dark, moist conditions; tight-fitting, close-toed shoes; locker room floors, communal showers and baths.
• Tinea corporis: invasive dermatophyte infection; immunocompromised host due to underlying conditions or immunosuppressive or steroid therapy.
• Onychomycosis: immunocompromised patients, HIV infection.

Epidemiology

Incidence and prevalence

Frequency

• 20% of people in the US are infected, more commonly in warmer climates.
• Prevalence of infection increases with age.
• 70% of adults experience tinea pedis.

Demographics

Age

• Tinea cruris: rare in children.
• Tinea pedis: prevalent in pubertal children and older people.
• Tinea capitis: common in prepubertal children with peak at 3-9 years of age.
• Tinea corporis: no age prevalence.

Gender

• Tinea cruris: common in men, rare in women.
• Tinea pedis: common in men, rare in women.

Geography

• Tinea capitis: mainly crowded inner city environments.
• Tinea corporis: common in tropical climates.

Socioeconomic status

• Tinea capitis: low income, crowded conditions.
• Occupations such as animal handler, veterinarian, zookeeper, farmer, and certain laboratory workers have an increased exposure potential.