Dermatophytosis Tinea Infections

Authored by , Reviewed by Dr Laurence Knott | Last edited | Meets Patient’s editorial guidelines

This article is for Medical Professionals

Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find the Fungal Groin Infection (Tinea Cruris) article more useful, or one of our other health articles.


Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit https://www.nice.org.uk/covid-19 to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.

Dermatophytosis (tinea) infections are fungal infections caused by dermatophytes - a group of fungi that invade and grow in dead keratin. Several species commonly invade human keratin and these belong to the Epidermophyton, Microsporum and Trichophyton genera. They tend to grow outwards on skin, producing a ring-like pattern - hence the term 'ringworm'. They are very common and affect different parts of the body. They can usually be successfully treated but success depends on the site of infection and on compliance with treatment.

See the separate Tinea Capitis, Fungal Nail Infections, Pityriasis Versicolor and Candidiasis articles.

  • Infection is limited to the dead layers of skin but encouraged by a damp and warm local environment.
  • The infection can be transmitted to humans by anthropophilic (between people), geophilic (from soil) and zoophilic (from animals) spread.
  • The most common organisms are:
    • Trichophytons rubrum, Trichophytons tonsurans, Trichophytons interdigitale and Trichophytons mentagrophytes.
    • Microsporum canis.
    • Epidermophyton floccosum.
  • Clinical classification is according to site:
    • Scalp - tinea capitis.
    • Feet - tinea pedis.
    • Hands - tinea manuum.
    • Nail - tinea unguium (or onychomycosis).
    • Beard area - tinea barbae.
    • Groin - tinea cruris.
    • Body including trunk and arms - tinea corporis.

Infection is very common all over the world. Some types are more common than others, with tinea pedis being most common in adults and tinea capitis the most common in children. Onychomycosis is also extremely common.

History

  • Itching, rash and nail discolouration are the most common symptoms of tinea infection.
  • Hair loss occurs with tinea capitis (mainly a disease of children).
  • Complications such as secondary infection (cellulitis and impetigo) can lead to symptoms.
  • It is common in people who play contact sports.
  • It occurs in immunocompromised patients.

Examination

  • Tinea pedis[4]:
    • It particularly affects the web of the toe where skin may be macerated and erythematous.
    • It commonly affects the plantar surface of the foot. Erythema, vesicles and pustules can occur.

    Tineas pedis - between toes

    Tinea pedis
    User Falloonb on en.wikipedia, Public domain, via Wikimedia Commons

    By Falloonb on en.wikipedia, Public domain, via Wikimedia Commons

  • Tinea capitis[5]:
    • It can cause hair loss with broken hairs at the surface (as distinct from alopecia areata).
    • Clinical appearance is variable, including scaly, crusting, pustules and/or black dot alopecia.
  • Tinea unguium (onychomycosis)[6]:
    • Onycholysis or separation of the nail from the nail bed commonly occurs.
    • Nail dystrophy with thickening and discolouration of the nail develops.
  • Tinea corporis[7]:
    • The skin lesions have annular scaly plaques with raised edges.
    • There may be vesicles and pustules.
    • Typically lesions are on exposed skin of the trunk, arms and legs (see 'Differential diagnosis', below).
    • More unusually the lesions can appear as overlapping concentric circles (tinea imbricate) or even herpetiform subcorneal vesicles or pustules (bullous tinea corporis).

Tinea corporis

Tinea corporis
Corina G., Public domain, via Wikimedia Commons

By Corina G., Public domain, via Wikimedia Commons

  • Tinea manuum:
    • Usually with tinea pedis.
    • Typically just affects one hand.
    • Scaling and redness are prominent.
    • Incorrect diagnosis and use of steroid may eventually exacerbate the infection.
  • Tinea cruris[8]:
    • Usually occurs in men.
    • Often tolerated for some time before presentation.
    • Typically erythematous with central clearing and raised edge.
  • Tinea barbae[9]:
    • Affects the beard area.
    • Redness, scaling and pustules are common.

Other annular rashes are often confused with tinea infections. Eczema and psoriasis are commonly confused with tinea. Pityriasis versicolor occurs all over the trunk while candida occurs as a flexural rash at extremes of age or in the immunocompromised, those with diabetes or patients on antibiotics.

Treatment with topical steroids often causes confusion, making tinea less scaly and more erythematous. Steroid use also makes the 'active' edge and the inactive centre less distinct (tinea incognito). Clinically the diagnosis can be difficult but, if it is a possibility, take scrapings for mycology. Other fungal infections look nothing like tinea. Other conditions to consider include:

  • Microscopy of skin and nail specimens may reveal hyphae and spores.
  • Fungal culture can identify the species but is not always reliable and it can take six weeks to obtain results.
  • Ultraviolet light (Wood's light) is useful for tinea capitis especially. Fluorescence is produced by the fungus. Fluorescence is not seen with tinea corporis or tinea cruris.
  • Rarely, a biopsy may be needed if the case is atypical or not responding to treatment.

Diabetes, immunocompromised states, atopy and Cushing's syndrome have all been associated with fungal infections.

  • Offer advice on hygiene measures:
    • Keep affected skin cool and dry.
    • Wear cotton, absorbent clothing.
    • Avoid scratching affected skin.
    • After washing, dry thoroughly.
    • Do not share towels, and wash frequently, to reduce the risk of transmission.
    • Cover feet in communal bathing pools, changing areas and gymnasiums if feet are affected.
    • Continue school and sporting activities.
  • See the separate Antifungal Medications article.
  • Topical agents containing a corticosteroid are not usually necessary. They may be used if there is a lot of skin inflammation. They should be used for a week only.
  • Referral may be needed if diagnosis is in doubt.

The main complication is secondary bacterial infection. Hair loss is a complication of tinea capitis. Pain and difficulty with shoes can result from onychomycosis.

Scarring is uncommon but more likely in people with pigmented skin. Scarring usually fades with time. Skin protection such as using a moisturiser cream and sunscreen can be helpful. Extensive or severe scarring may need further treatment, such as using laser therapy.

Excellent with good compliance and subsequent precautions to avoid repeat infection.

  • Good skin hygiene.
  • Good nail hygiene.
  • Avoiding prolonged wetting or dampness of the skin and feet.
  • Avoiding trainers, which can retain sweat and promote a warm, moist environment.
  • Treatment of tinea pedis - helps prevent onychomycosis[6].
  • Wearing clean, loose-fitting underwear. 

Further reading and references

  1. Martinez DA, Oliver BG, Graser Y, et al; Comparative genome analysis of Trichophyton rubrum and related dermatophytes reveals candidate genes involved in infection. MBio. 2012 Sep 43(5):e00259-12. doi: 10.1128/mBio.00259-12. Print 2012.

  2. The Cutaneous Mycoses; Mycology Online

  3. Hainer BL; Dermatophyte infections. Am Fam Physician. 2003 Jan 167(1):101-8.

  4. Fungal skin infection - foot; NICE CKS, April 2018 (UK access only)

  5. Fungal skin infection - scalp; NICE CKS, April 2018 (UK access only)

  6. Fungal nail infection; NICE CKS, March 2018 (UK access only)

  7. Fungal skin infection - body and groin; NICE CKS, May 2018 (UK access only)

  8. Tinea Cruris; DermNet NZ

  9. Tinea barbae; DermNet NZ

  10. Fungal Skin and Nail Infections: Diagnosis and Laboratory Investigation - Quick Reference Guide for Primary Care; GOV.UK, 2017

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