section name header

Information

Editors

AlexanderSalava

Dermatomycoses

Essentials

  • Before starting treatment, make sure that the patient does have a fungal infection and not another skin problem resembling it. Ringworm can be confirmed by obtaining fungal specimens.
  • Typical inguinal ringworm (tinea cruris) or tinea in the interdigital spaces between the toes can be treated topically case by case based on the clinical picture.
  • To avoid unnecessary use of antifungal drugs, onychomycosis should always be confirmed by obtaining a fungal specimen before starting the treatment. In addition, starting treatment without obtaining a fungal specimen will prevent reliable mycological diagnosis for several months.
  • Most of the infections are caused by dermatophytes. Yeasts and moulds occur normally on the skin, nails and mucosa, and such a finding in a specimen does not necessarily mean that the infection is caused by these. The findings must be interpreted carefully in relation to the clinical picture.
  • Remember the adverse effects of antifungal drugs and the possible interactions with other drugs. Consult locally available drug databases and other information sources.

Infection

  • Ringworm is caused by dermatophytes, such as the Trichophyton, Epidermophyton or Microsporum genera. Yeasts colonizing the skin include the Candida and Malassezia genera.
  • Acquiring a dermatophyte infection is much more rare than being exposed to them.
  • Genetic factors play a role in the infectiousness of foot ringworm, for example.
  • Dermatomycoses and onychomycoses occur more commonly in athletes, elderly people and immunosuppressed patients. They are common in tropical and subtropical countries (which must be kept in mind if the patient has moved from such an area or spent prolonged periods there).
  • Ringworm infections of domestic animals (e.g. cows, guinea pigs, cats) spread easily to humans and cause ringworm of the scalp or circular patches on the extremities, trunk, or even the face.

Obtaining a fungal specimen

  • Prior to taking a fungal specimen from the skin, topical antifungal medication must not be used for two weeks or oral medication for two months. Prior to taking a sample from a nail, antifungal nail varnish (e.g. amorolfine nail lacquer) must not be used for 3 months and oral antifungal drugs for 6 months. See table T1.
  • Clean the skin with an alcohol solution and scrape (using scalpel no. 15, for example) scales from the margin of the lesion into a folded paper or a dry tube and send the specimen to the laboratory by ordinary mail. Hairs or blister roofs can also be used as specimens. From a nail, slices should be cut or carved at the margin between the healthy and affected nail, and the hyperkeratotic mass under the nail should also be scraped and included in the specimen.
  • As much material as possible should be collected because the specimen is used both for microscopy (fungal microscopy) and for culture (fungal culture).
    • The laboratory performs microscopy (native examination and examination with potassium hydroxide) and fungal culture.
    • Detection of filamentous fungi in a native examination suggests a fungal infection but only demonstration of the fungi in the culture confirms the diagnosis.
    • The results of the native examination are obtained in a few days, but the results of the culture are available only after 2 to 4 weeks.
    • If the result is negative and mycosis is strongly suspected, take new samples making sure that no antifungals have been used (see time required between end of medication and taking culture specimen).
  • Fast dermatophyte-specific methods that are based on nucleic acid amplification are available. The dermatophyte, nucleic acid test detects the most common dermatophytes and yeasts. The indications for its use and its benefits in the diagnosis of dermatomycoses and onychomycoses are still unclear.

Time required between the end of antifungal medication and taking culture specimen

External antifungal drug (e.g. cream)Antifungal nail varnish/polish (e.g. amorolfine lacquer)Systemic antifungal drug
Fungal culture from skin2 weeks-2 months
Fungal culture from nail2 weeks3 months6 months
According to current knowledge, antifungal drugs do not influence the results of nucleic acid detection tests, since these can also detect DNA from dead dermatophytes (PCR technique).

Antifungal drugs Continuous Terbinafine Compared with Intermittent Itraconazole in Treatment of Toenail Onychomycosis

General remarks

  • A dermatophyte infection of the scalp or nails requires systemic medication.
  • A dermatophyte infection of the skin is treated either with topical Topical Antifungal Treatments for Tinea Cruris and Tinea Corporis or systemic medication or with both depending on the spread of the infection. Systemic medication may sometimes be needed if topical treatments are not sufficient to cure confirmed ringworm.
  • In onychomycosis, a permanent cure (= clinical cure after follow-up of 1-2 years) is obtained in about half of the patients.

Indications

Adverse effects and interactions

  • Interactions must be checked when using antifungal agents! Even topical antifungals applied to the skin or to the mucosa, in particular, may also have interactions with other drugs.
  • Terbinafine: abdominal symptoms, drug-induced dermatitis, joint and muscle symptoms, loss of taste, some interactions
  • Itraconazole and fluconazole: abdominal symptoms, headaches, drug-induced dermatitis; many, partly dangerous, interactions with other drugs metabolized by the CYP3A4 enzyme.
  • Laboratory monitoring during systemic medication: elevated liver values and changes in blood count have been reported in association with the use of terbinafine, itraconazole and fluconazole (and griseofulvin).
    • Liver values should be checked before starting drug treatment, particularly if the patient has risk factors, such as a liver disease.
    • Basic blood count with platelet count, ALT, and possibly creatinine can be checked case by case before treatment and at 1-2 months.
    • Blood tests should be done more readily in children before treatment and every 2-4 weeks during treatment.

Antifungal resistance

  • In recent years, both clinical treatment resistance and antimicrobial resistance have been increasingly reported in skin and nail infections caused by dermatophytes (especially in warm climate countries).
    • Terbinafine resistance appears to be much more common than azole group resistance.
    • In certain strains of dermatophytes (e.g. Trichophyton indotineae, Trichophyton rubrum), terbinafine resistance has been reported more frequently.
  • The reasons for the development of antimicrobial resistance are still unclear, but it is possible that too small drug doses or amounts of ointments, too short courses, combination of antifungals with glucocorticoids and the increase in immunocompromised patients (underlying diseases, medication) have affected this.
  • Find out about locally relevant data on dermatophyte resistance to antimicrobials.
  • If resistance is suspected, changing the antifungal drug, extending the course of treatment or a combination of systemic and topical antifungal therapy may help.
    • In some cases, combination therapy of two systemic antifungals or other systemic antifungals have also been used (consulting specialized care is recommended).

Athlete's foot (tinea pedis) Topical Treatments for Fungal Infections of the Skin and Nails of the Foot

Clinical picture

  • Clinical pictures include maceration between the toes (most common, picture 1), dry, hyperkeratotic scaling on the sole of the foot (moccasin ringworm), vesicular (small fluid-filled blisters, erythema) and acute ulcerative (ulcers, erosion) pictures.
    • Most common between the 4th and 5th toes.
    • The skin between the toes is erythematous, macerated, and there may be ulceration and vesicles in the area.
    • The lesions are often itchy and may spread to the top of the foot as circular scaling lesions.
    • A secondary bacterial infection may occur.
    • Athlete's foot may be associated with id reactions (mycids) on the palms and between fingers.
  • Moccasin ringworm (pictures 23 )
    • Often there are no subjective symptoms (picture 4).
    • The plantar skin is slightly hyperkeratotic, erythematous, and scaling.
    • The fungal infection may be unilateral or may affect only the distal part of the foot (picture 5).
    • Similar ringworm may occur unilaterally on the palm of a hand (picture 6).
  • Athlete's foot may be complicated by erysipelas or cellulitis (ringworm between toes forming the portal of entry for infection), an id reaction (itchy vesicles on hands or feet) or deep folliculitis (Majocchi granulomas).

Differential diagnosis

  • Macerated skin and acute ulcerative ringworm between the toes: irritant contact dermatitis and maceration, allergic contact eczema, bacterial inflammation (such as impetigo or a gram-negative infection between the toes), erythrasma between the toes
  • More extensive athlete's foot or moccasin ringworm: atopic eczema (atopic winter feet), allergic contact eczema (from topical skin care products, for example), psoriasis, palmoplantar pustulosis

Aetiology

  • The most common causative agent is Trichophyton rubrum, more rarely T. mentagrophytes, and very rarely Epidermophyton floccosum.
  • Candida may also be isolated from macerated skin between the toes but this does not indicate a direct pathogenic role.

Treatment

Onychomycosis (tinea unguium)

Clinical picture

  • Occurs commonly in the toenails, infrequently in the fingernails (pictures 7 8)
  • Onychomycosis usually begins distally under the nail, spreads linearly along its lateral part towards the base of the nail, thickens and loosens the nail, and causes discolouration (picture 9). Eventually the nail is completely damaged (picture 10).
  • Onychomycosis patients often have simultaneous interdigital tinea or moccasin ringworm on the soles of the feet.
  • Risk factors: advanced age, diabetes, immunosuppression, ASO, neuropathies, structural foot deformities, physical exercise and hobbies involving compression of the feet, recurrent nail trauma

Differential diagnosis

  • Traumatic nail dystrophy (e.g. in soccer players; the cause is not one detectable traumatic incident but constant pressure or repeated microtrauma, which may cause permanently disturbed nail growth)
  • Nail psoriasis Psoriasis
  • Rare intrinsic nail disorders (such as trachonychia, twenty nail dystrophy)
  • Rare genetic nail or skin disorders Nail Lesions and Disorders

Treatment

  • The diagnosis should be verified by taking a fungal sample.
  • Topical treatment with antifungal nail varnish (amorolfin, ciclopirox or tioconazole nail varnish) may be effective in onychomycosis that is restricted to the distal end of the nail.
  • Application of urea ointment to soften the nail, performed by a foot health practitioner, may improve the treatment results in the case of thick, deformed nails.
  • The most efficient therapy for onychomycosis is terbinafine , but only about one half of the patients will be completely cured by this drug, too. The dosage is 250 mg once daily for 3 to 4 months for toenails and 6 weeks for the treatment of fingernails.
  • Itraconazole should be administered as pulse therapy: 200 mg twice daily at meals for one week every 4 weeks for 3 to 4 months.
  • Take into account the interactions of itraconazole with other drugs.
  • Systemic medication can be combined with topical treatment (nail varnish and/or creams) for possibly better results.
  • In children, primarily topical treatments (nail varnishes off-label and antifungal creams) have been used. In select cases with more severe or treatment-resistant disease, also systemic medication has been used.
  • In elderly patients, treatment results in onychomycosis are worse than in younger patients.

Inguinal ringworm (tinea cruris)

Clinical picture

  • A unilateral, itching, well-demarcated ring or several concentric rings, erythematous at the margins, particularly, are often observed initially, at least (picture 11).
  • Mycotic folliculitis or even small abscesses may be detected in the lesion and in the surroundings, especially after treatment with local glucocorticoids (tinea incognito).
  • Inguinal ringworm is most commonly encountered in men.

Differential diagnosis

  • Maceration (intertrigo), irritant contact dermatitis, inverse psoriasis, erythrasma, allergic contact eczema

Treatment

Ringworm of the body (tinea corporis)

General remarks

  • The clinical picture varies from one ring-shaped lesion to a more widespread eruption where the central area may already be healing (picture 12). In suspicion of ringworm of the body, a specimen for specific fungal diagnosis is always required before starting the treatment.
  • Some of the infections may be of animal origin. The cutaneous symptoms may be more pronounced than in other fungal infections; even suppuration may occur.
  • Assessing the history of animal contacts (guinea pig, cat, dog, cattle) helps towards the diagnosis which can be confirmed by fungal culture.
  • A fungal skin disease caused by Trichophyton tonsurans has been encountered among wrestlers. Epidemics may occur among athletes.

Differential diagnosis

  • Eczemas (atopic and nummular eczema, in particular), cutaneous psoriasis, and in single patches also superficial basal cell carcinoma

Treatment

  • Similar to inguinal ringworm (see above).
  • In widespread disease systemic medication may be indicated.

Scalp ringworm (tinea capitis)

General remarks

  • The diagnosis should always be based on positive findings in a fungal specimen that is taken before the commencement of treatment.
  • The causative agent is usually Microsporum canis (from cats) or T. mentagrophytes (from several kinds of pets). T. violaceum (in people who have moved from endemic regions), Microsporum audouinii, T. tonsurans, and T. soudanense are rare.

Clinical picture

  • There may be one or several scaly patches on the scalp, with broken or missing hairs (picture 13). There may also be suppuration on the scalp.
  • Sometimes an abscess-like mass (kerion), a very rapidly progressive, pus-forming infection is seen. It requires a rapid start of treatment to prevent permanent hair loss.
  • Take skin scales and also broken hair stumps with forceps for fungal culture. If there is pus it should also be sampled (into a separate test tube). In cases of kerion the treatment should start immediately based on native sample investigation - waiting for culture results may make the patient bald.
  • Other members of the family should be examined and treated simultaneously in order to prevent the spread of the disease.
  • Items used for hair care (combs, brushes, clips, etc.) must not be shared with others.

Differential diagnosis

  • Seborrhoeic eczema, atopic scalp eczema, cutaneous psoriasis, neurodermatitis, scalp folliculitis, scalp impetigo and bacterial inflammation

Treatment Treatment of Tinea Capitis, Systemic Antifungal Therapy for Tinea Capitis in Children

  • For adults: terbinafine at a dose of 250 mg once daily or itraconazole at a dose of 200 mg once daily for 4 to 6 weeks
  • In the acute phase, topical medication may be combined with the treatment.
  • Unofficial dosage recommendations for children (in Finland):
    • Terbinafine (official indication HASH(0x2fdd348) 18 years, little experience of use in children)
      • <20 kg: 62.5 mg/day
      • 20-40 kg: 125 mg/day
      • >40 kg: 250 mg/day
    • Itraconazole (no official indication in children, oral solution 10 mg/ml): 3-5 mg/kg/day as single doses or divided into two doses
      • 10-17 kg: 100 mg/day every other day
      • 18-27 kg: 100 mg/day
      • 28-41 kg: 100 mg/day, or 100 mg/day and 200 mg/day on alternate days
      • 42-50 kg: 100 mg/day and 200 mg/day on alternate days
    • Monitoring by blood tests (basic blood count with platelet count, ALT, possibly creatinine) is recommended for children before drug treatment and every 2-4 weeks during the treatment.

General remarks about cutaneous yeast infections (candidiasis)

  • Cutaneous yeast infections (candidiasis) are vastly over-diagnosed.
    • Diseases falsely labelled as candidiasis include lichen ruber planus, "stomatodynia" and atopic eczema in the angles of the mouth.
    • In skin folds the cause may be seborrhoeic eczema, maceration (intertrigo) or inverse psoriasis.
    • "Candidal balanitis" Balanitis, Balanoposthitis and Paraphimosis in the Adult is in most cases a form of seborrhoeic eczema.
    • "Candidal intertrigo" between the fingers may be toxic eczema Irritant Contact Dermatitis.
  • The most common aetiological agent of true yeast infection is Candida albicans. The infection usually occurs on a skin area that has already been otherwise damaged (moisture, chafing, etc.).
  • Isolating Candida albicans from a culture specimen does not prove that it is the pathogenic agent, because candida may be a human saprophyte.
  • In candidiasis occurring in elderly persons in the angles of the mouth, under the breasts, and in the inguinal folds, the affected skin area is macerated, there is often ulceration at the base of the folds, and small satellite lesions may be seen at the margins.
  • Predisposing factors include, e.g., diabetes, long-term antimicrobial treatments, immunosuppression, and dental prostheses.

Oral yeast infections (candidiasis)

Clinical picture

  • Typical white exudates on the oral mucosa, usually on the tongue, in infants at the age of a few weeks
  • More infrequent in adults than expected, and often difficult to diagnose. Both exudative and atrophic forms of the disease exist.

Treatment

Candidal angular cheilitis

Clinical picture

  • Occurs with concomitant oral candidiasis or even alone.
  • Loss of vertical dimension of occlusion (bite collapse) often associated with a dental prosthesis, deepens the skin fold in the angle of the mouth, keeps it moist, and predisposes the subject to candidiasis (picture 14).
  • See also Cheilitis Cheilitis.

Treatment

  • Azole ointment; sometimes a combination ointment to treat secondary eczema and bacterial infection in courses of 1-2 weeks.
  • The disease tends to recur, and the treatment must be repeated from time to time.

Candidal intertrigo

Clinical picture

  • Avoid over-diagnosis: often the cause is maceration (intertrigo), irritant contact dermatitis, seborrhoeic eczema (particularly in the anal region) or psoriasis of the skin folds.
  • Occurs under the breasts, in the navel, in the inguinal folds, between the buttocks, and between fingers.
  • The area is erythematous, tender and oozing, and there may be satellite papules around the lesion (picture15).

Treatment

Candidal paronychia

Clinical picture

  • This is usually an irritant contact eczema of the nail folds (excessive washing of hands, wet work, maceration under protective gloves), possibly involving a mixed secondary infection: Candida albicans + Staph. aureus.
  • Occupational risk groups include cold buffet managers, cleaners, kitchen personnel and health care personnel, for instance
  • In chronic paronychia Paronychia and Ingrown Toenail, transverse lines and unevenness may be seen on the nail plate.
  • An acute disease does not usually damage the nail permanently.

Treatment

Candidal balanitis

General remarks

  • A part of the cases diagnosed as candidal balanitis are actually seborrhoeic eczema.
  • The disease is usually mild and may clear spontaneously.
  • Over-diagnosis of candidiasis causes unnecessary concern and trouble for the spouse - the female partner may have yeast even if symptomless.

Clinical picture

  • The symptoms of candidial balanitis include itching and smarting.
  • Erythematous erosions and white exudates can be seen on the mucosal membranes.

Treatment

    References

    • Gupta AK, Foley KA, Mays RR et al. Monotherapy for toenail onychomycosis: a systematic review and network meta-analysis. Br J Dermatol 2020;182(2):287-299. [PubMed]
    • Thomas J, Peterson GM, Christenson JK et al. Antifungal Drug Use for Onychomycosis. Am J Ther 2019;26(3):e388-e396. [PubMed]
    • Gupta AK, Versteeg SG, Shear NH et al. A Practical Guide to Curing Onychomycosis: How to Maximize Cure at the Patient, Organism, Treatment, and Environmental Level. Am J Clin Dermatol 2019;20(1):123-133. [PubMed]
    • Gupta AK, Mays RR, Versteeg SG et al. Onychomycosis in children: Safety and efficacy of antifungal agents. Pediatr Dermatol 2018;35(5):552-559. [PubMed]
    • van Zuuren EJ, Fedorowicz Z, El-Gohary M. Evidence-based topical treatments for tinea cruris and tinea corporis: a summary of a Cochrane systematic review. Br J Dermatol 2015;172(3):616-41. [PubMed]
    • Rotta I, Sanchez A, Gonçalves PR et al. Efficacy and safety of topical antifungals in the treatment of dermatomycosis: a systematic review. Br J Dermatol 2012;166(5):927-33. [PubMed]
    • Foley K, Gupta AK, Versteeg S, et al. Topical and device-based treatments for fungal infections of the toenails. Cochrane Database Syst Rev 2020;(1):CD012093. [PubMed]
    • Gupta AK, Mays RR, Versteeg SG, et al. Onychomycosis in children: Safety and efficacy of antifungal agents. Pediatr Dermatol 2018;35(5):552-559. [PubMed]