Publish date: Posted on
Last updated: November 27, 2024
Keywords #
tinea corporis
tinea capitis
tinea pedis
tinea cruris
dermatomycosis
jock itch
athlete’s foot
ringworm
Diagnosis #
Tinea is a superficial infection caused by dermatophytes or filamentous fungi that invade keratinized skin.[1] Body location is denoted by the descriptors capitis (the scalp), pedis (the feet and soles), cruris (the groin), unguium or onychomycosis (the nails), and corporis (body regions other than scalp, feet, palms, or groin). The most common causative organisms of tinea include trichophyton, epidermophyton, and microsporum.[1] Tinea infections have a characteristic rash, most recognizable as an erythematous, scaly, annular plaque with a raised outer edge and central clearing. Individuals affected typically experience intense pruritus at the site of the lesion, accompanied sometimes by maceration of the skin, signs of inflammation or secondary infection, and discomfort. [2]
Individuals with diabetes mellitus, occlusive clothing, excessive perspiration, improper hygiene, or immunocompromised states may be at increased risk of tinea. Additionally, close personal contact with the skin of affected individuals (i.e., athletes of contact sports) may increase risk of infection with tinea.[1] Animal vehicles are known to transmit dermatophytes, as well as autoinfection from transfer of infected scale to other parts of the body.[3]
Key Concepts #
- Tinea is a superficial fungal infection, precipitated by exposure from animals, close personal contact, or autoinfection.
- Topical or oral antifungal therapy are effective treatments.
- Primary and secondary preventions are achieved through proper personal hygiene, keeping skin cool and dry, adequate antifungal therapy, avoidance of contact with animals, maintaining clean clothes, and avoiding sharing towels or hair products with affected individuals.[4]
- Diagnosis is primarily clinical and can be confirmed via KOH preparation of scale.
Epidemiology #
Tinea is not an uncommon condition, affecting at any given time between 20-25% of the world’s population. Epidemiological data suggest that different body areas are affected disproportionately between different groups; namely, there is a predilection for tinea corporis and tinea unguium among women, and for tinea cruris and pedis among men.[5] Children are more likely to develop tinea corpora and capitis, and teens and adults generally contract tinea cruris, pedis, and unguium.[3] Additionally, residents of areas of high humidity and hot temperatures are more prone to cutaneous fungal infections.[1]
Clinical Features #
- Tinea in all locations on the body generally presents as a pruritic, erythematous rash.
- It is typically annular with scale and central clearing.
- The border of the lesion is often raised or “heaped up” and may increase in size as the lesion develops.
- Lesions may be single or multiple, and neighboring lesions may coalesce forming a single, larger lesion.
The size of each plaque may be between 1 to 5 cm.[3]
Differential Diagnoses #
- Psoriasis
- Atopic dermatitis
- Erythema multiforme
- Nummular eczema
- Pityriasis rosea
- Contact dermatitis
- Candidal intertrigo
Diagnostic Workup #
A detailed history and physical exam are generally enough to diagnose tinea in all body regions. However, prior to starting treatment, it is recommended that clinicians confirm the diagnosis with laboratory techniques. Branching hyphae visualized on 10-20% KOH preparation of scale scrapings is diagnostic and may be performed at point of care in the clinic. Additional testing, namely skin biopsy with PAS stain, is rarely indicated and only for atypical or chronic lesions.[3]
Treatment #
Tinea corporis, pedis, and cruris are often effectively treated with topical antifungal creams. These are applied between two and four times daily for up to four weeks. Importantly, affected areas should be properly cleaned and dried prior to medication application. Socks, clothes, and other garments should be moisture-wicking to keep affected areas from becoming overly moist throughout the day.[6]
Topical antifungals are unable to penetrate the hair shaft and nail bed; thus, systemic oral antifungal medications are indicated for tinea capitis and tinea unguium. Terbinafine is the recommended agent for both conditions, with duration of therapy generally between two and six weeks for tinea capitis, and three to six months for onychomycosis. Treatment is largely very effective for tinea capitis, however, tinea unguium is generally more persistent, and oral therapy is ineffective in up to 50% of cases. Resolution of onychomycosis is slow, as the new nail matrix takes between six and 18 months to grow.[3] Combination treatment with 1% or 2.5% selenium sulfide shampoo or 2% ketoconazole shampoo reduces transmission of tinea capitis during the first two weeks of oral therapy.[3]
Slide Viewer #
https://utahderm.med.utah.edu/image-viewer/References #
- Gupta AK, Chaudhry M, Elewski B. Tinea corporis, tinea cruris, tinea nigra, and piedra. Dermatol Clin. 2003(21) 395-400.
- Molina de Diego A. Clinical, diagnostic, and therapeutic aspects of dermatophytosis. Enferm Infecc Microbiol Clin. 2011(29) Suppl 3:33-9.
- Ely JW, Rosenfeld S, Seabury Stone M. Diagnosis and management of tinea infections. Am Fam Physician. 2014 Nov 15;90(10):702-10.
- Tampieri MP. Update on the diagnosis of dermatomycosis. Parassitologia. 2004(46) 183-6.
- Singh S, Verma P, Chandra U, Tiwary NK. Risk factors for chronic and chronic-relapsing tinea corporis, tinea cruris and tinea faciei: Results of a case–control study. Indian J Dermatol Venereol Leprol 2019;85:197-200
- Vena GA, Chieco P, Posa F, Garofalo A, Bosco A, Cassano N. Epidemiology of dermatophytoses: retrospective analysis from 2005 to 2010 and comparison with previous data from 1975. New Microbiol. 2012 Apr;35(2):207-13.
- Sahoo AK, Mahajan R. Management of tinea corporis, tinea cruris, and tinea pedis: A comprehensive review. Indian Dermatol Online J. 2016 Mar-Apr;7(2):77-86.
