Dermatophyte infections

Miconazole is primarily used externally for Candida and dermatophyte infections of the skin and vaginal candidosis as well as for acute internal mycoses. Synonyms of this drag are acnidazil, dactar, dermonistate, and others. 

Undecylenic acid, like zinc undecylenate, is very effective as an external drag for treating moderate dermatophyte infections and yeast dermatitis, but it is not effective for shingles and for Candida infections. Synonyms of this drug are benzevrine, micocid, undetin, and others. 

Tolnaftate is used as an external drag for moderate dermatophyte infections (shingles), and it is not effective for treating Candida infections. Synonyms of this drag are tinatox, tonof-tal, timoped, tinaderm, tinactin, and others. 

Treatment of severe recalcitrant cutaneous dermatophyte infections not responding to topical therapy or oral griseofulvin or in patients unable to take griseofulvin. 

Minimum treatment of recalcitrant dermatophyte infections is 4 weeks in cases involving glabrous skin. Palmar and plantar infections may respond more slowly. 

Griseofulvin is an antifungal antibiotic used for treating common dermatophyte infections. It is inactive against yeasts. It is available in some countries as a solution which can be applied to the affected areas. However griseofulvin is mostly used systemi-cally. 

Terbinatine is closely related to naftiflne and has similar activity. It is used for the topical treatment of dermatophyte infections. It can give local irritation and erythema and care should be taken to avoid contact with eyes and mucous membranes. 

Tolnaftate is topically effective against various dermatophyte infections. It has also activity against Pityrosporum orbiculare but not against Candida species. Local irritation and contact sensitization are rare adverse effects. 

Griseofulvin Fulvicin, Grifulvin V) has been used safely and effectively for decades for dermatophyte infections of scalp and nails and for more widespread skin eruptions. However, infections in certain sites (e.g.. toenails) respond poorly. The drug is generally well tolerated, even in the long-term courses necessary for nail disease. 

Ketoconazole Nizoral) is approved for treating dermatophyte infections unresponsive to griseofulvin and for patients unable to tolerate that drug. A single oral... 

Many effective topical agents are available both with and without a prescription for treating cutaneous dermatophyte infections and seborrheic dermatitis (Table 41.3) the azole drugs are also active against superficial candidal infections. 

Despite negligible cerebrospinal fluid concentrations, itraconazole shows promise in the treatment of cryptococcal and coccidioidal meningitis. Additional uses for itraconazole include treatment of vaginal candidiasis, tinea versicolor, dermatophyte infections, and onychomycosis. Fungal naU infections account for most use of this drug in the outpatient setting. 

Ketoconazole remains useful in the treatment of cutaneous and mucous membrane dermatophyte and yeast infections, but it has been replaced by the newer triazoles in the treatment of most serious Candida infections and disseminated mycoses. Ketoconazole is usually effective in the treatment of thrush, but fluconazole is superior to ketoconazole for refractory thrush. Widespread dermatophyte infections on skin surfaces can be treated easily with oral ketoconazole when the use of topical antifungal agents would be impractical. Treatment of vulvovaginal candidiasis with topical imidazoles is less expensive. 

Miconazole (Monistat) is a broad-spectrum imidazole antifungal agent used in the topical treatment of cutaneous dermatophyte infections and mucous membrane Candida infections, such as vaginitis. Minimal absorption occurs from skin or mucous membrane surfaces. Local irritation to skin and mucous membranes can occur with topical use headaches, urticaria, and abdominal cramping have been reported with treatment for vagiiutis. 

In the treatment of ringworm of the beard, scalp, and other skin surfaces, 4 to 6 weeks of therapy is often required. Therapy failure may be to the result of an incorrect diagnosis superficial candidiasis, which may resemble a dermatophyte infection, does not respond to griseofulvin treatment. Onychomycosis responds very slowly to griseofulvin (1 year or more of treatment is commonly required) and cure rates are poor itraconazole and terbinafine hydrochloride are more effective than griseofulvin for onychomycosis. 

Ciclopirox olamine (Loprox) is a pyridone derivative available for the treatment of cutaneous dermatophyte infections, cutaneous C. albicans infections, and tinea versicolor caused by Malassezia furfur. It interferes with fungal growth by inhibiting macromolecule synthesis. 

Tolnaftate (Tinactin, others) is a nonprescription antifungal agent effective in the topical treatment of dermatophyte infections and tinea. The mechaitism of action is unknown. 

The two azoles most commonly used topically are clotrimazole and miconazole several others are available (see Preparations Available). Both are available over-the-counter and are often used for vulvovaginal candidiasis. Oral clotrimazole troches are available for treatment of oral thrush and are a pleasant-tasting alternative to nystatin. In cream form, both agents are useful for dermatophytic infections, including tinea corporis, tinea pedis, and tinea cruris. Absorption is negligible, and adverse effects are rare. 

Once- or twice-daily application to the affected area will generally result in clearing of superficial dermatophyte infections in 2-3 weeks, although the medication should be continued until eradication of the organism is confirmed. Paronychial and intertriginous candidiasis can be treated effectively by any of these agents when applied three or four times daily. Seborrheic dermatitis should be treated with twice-daily applications of ketoconazole until clinical clearing is obtained. 

Tolnaftate is a synthetic antifungal compound that is effective topically against dermatophyte infections caused by epidermophyton, microsporum, and trichophyton. It is also active against P orbiculare but not against Candida. 

Fluconazole is well absorbed following oral administration, with a plasma half-life of 30 hours. In view of this long half-life, daily doses of 100 mg are sufficient to treat mucocutaneous candidiasis alternate-day doses are sufficient for dermatophyte infections. The plasma half-life of itraconazole is similar to that of fluconazole, and detectable therapeutic concentrations remain in the stratum corneum for up to 28 days following termination of therapy. Itraconazole is effective for the treatment of onychomycosis in a dosage of 200 mg daily taken with food to ensure maximum absorption for 3 consecutive months. Recent reports of heart failure in patients receiving itraconazole for onychomycosis have resulted in recommendations that it not be given for treatment of onychomycosis in patients with ventricular dysfunction. 

Antifungals applied topically are used to treat dermatophytic infections caused by Trichophyton and Microsporum species. Ringworm is the most common and widely known of such fungal skin diseases of animals and birds. In recent years, a number of reports have appeared drawing attention to the high incidence of human ringworm caused by fungi from animals. The public health aspects of the disease is of considerable importance, whereas the economic impact to the farmer is yet not clearly defined. 

Terbinafine (Lamisil) is an allylamine with activity similar to that of naftifine hydrochloride. It is available as a 1% cream and solution for the topical treatment of dermatophyte infections. 

Identification of a particular fungal pathogen is essential in many respects it will have an important role in therapeutic decision-making as in otomycosis, and with the arrival of the new antifungals it has become important to differentiate between yeast and dermatophyte infection as well as between dermatophytes themselves, as they may not respond similarly. Identification of the pathogen may also lead to the source of an infection and therefore enable initiation of measures against spread. 

This dermatophyte infection confined to the trunk and extremities takes a subacute to chronic course (weeks to years) and produces the typical and rather well-known lesion called ringworm (fig. 1), a usually round, often irregular scaly lesion with a significantly more inflamed, raised border containing a... 

This dermatophyte infection of the scalp and hair of sometimes quite striking appearance is reported to have had tremendous influence on the lives of people in old times subjects with tinea capitis were allowed to keep their heads covered in the presence of the monarch, and sometimes were not allowed to emigrate to the United States [19]. Although such drastic measures are historical anecdotes, tinea capitis nevertheless may lead to some social discomfort even today. 

Fig. 4. Onychomycosis. Another typical manifestation of dermatophyte infection, starting from the distal border of the nail. 

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