Medication Summary
Tinea corporis infections may be treated with topical agents (ie, creams, lotions, solutions, powders, sprays) as the drug of choice or with oral antifungals in extensive or recalcitrant disease. [8, 9]
For tinea capitis and nail infections, topical therapy is ineffective. Findings with onychomycosis treatment were discouraging because of the need for prolonged therapy and the low success rate. However, in recent years, new oral antimycotic drugs have been developed as the drug of choice; these have greatly improved the outlook (especially for patients with fungal toenail infection). [10, 11, 12]
Use of oral medications requires baseline liver function testing and repeat laboratory testing half way through the typical 3-month course. Cultures are also recommended when managing children, as oral medications are more difficult for this age group. [13]
Medication classes
Two classes of antifungal medications are most commonly used: azoles and the allylamines. Both classes have the common endpoint if inhibiting ergosterol production.
Azoles inhibit lanosterol 14-alpha-demethylase, an enzyme that converts lanosterol to ergosterol (important for the fungal cell wall). This leads to permeability and renders the fungus unable to reproduce.
Allylamines inhibit squalene epoxidase, an enzyme that converts squalene to ergosterol, leading to the accumulation of toxic levels of squalene in the cell and cell death.
Antifungals
Class Summary
The optimal duration of topical therapy for dermatophytic infections of the skin has never been established. [14] In most cases of tinea corporis and tinea cruris, 2 weeks of treatment may suffice. Tinea pedis may require treatment for as long as 8 weeks.
Ketoconazole topical (Nizoral, Extina, Ketodan, Xelogel)
Imidazole, broad-spectrum antifungal agent indicated for the topical treatment of tinea corporis, tinea cruris, and tinea pedis. Inhibits synthesis of ergosterol (main sterol of fungal cell membranes), causing cellular components to leak; results is cell death.
Clotrimazole 1% cream or lotion (Lotrimin AF, Alevazol, Clotrimazole Anti-Fungal, Desenex)
Indicated for topical treatment of tinea corporis, tinea cruris, and tinea pedis. Broad-spectrum antifungal agent that inhibits yeast growth by altering cell membrane permeability, causing fungal cell death.
Econazole topical (Ecoza)
Effective in cutaneous infections. Interferes with RNA and protein synthesis and lipid metabolism. Disrupts fungal cell-wall membrane permeability, causing fungal cell death.
Miconazole topical (Mikaderm, Micatin, Podactin, Secura Antifungal, DermaFungal)
Damages fungal cell-wall membrane by inhibiting biosynthesis of ergosterol. Membrane permeability is increased, causing nutrients to leak and resulting in fungal-cell death. The lotion is preferred in intertriginous areas. If the cream is used, apply sparingly to avoid maceration effects.
Terbinafine (Lamisil)
Synthetic allylamine derivative that inhibits squalene epoxidase, a key enzyme in sterol biosynthesis of fungi, resulting in a deficiency in ergosterol that causes fungal cell death. Use until symptoms significantly improve.
Naftifine 1% cream (Naftin)
Indicated for the treatment of tinea corporis, tinea cruris, and tinea pedis. Broad-spectrum antifungal agent that appears to interfere with sterol biosynthesis by inhibiting the enzyme squalene 2,3-epoxidase. This inhibition results in decreased amounts of sterols, causing cell death. If no clinical improvement occurs after 4 weeks of treatment, reevaluate the patient.
Griseofulvin (Gris-PEG, Grifulvin V)
Extensively used in the past to treat dermatophytic infections of the skin. However, with new antifungals now available, use is now limited. An antibiotic derived from a species of Penicillium that is deposited in the keratin precursor cells, which are gradually replaced by noninfected tissue; the new keratin then becomes highly resistant to fungal invasions. Most used therapy for treating tinea capitis, especially if caused by M canis.
Itraconazole (Sporanox)
Synthetic triazole antifungal agent that inhibits fungal cell growth by inhibiting the cytochrome P-450–dependent synthesis of ergosterol, a vital component of fungal cell membranes.
A 30-d course of 100 mg of itraconazole daily has been shown to effectively treat tinea capitis. This treatment could prove to be a beneficial alternative to griseofulvin therapy.
Fluconazole (Diflucan)
Broad-spectrum triazole antifungal agent. A potent and selective inhibitor of fungal enzymes necessary for ergosterol synthesis. Most commonly used in the treatment of candidiasis.
Sertaconazole nitrate cream (Ertaczo)
Topical imidazole antifungal active against T rubrum, T mentagrophytes, E floccosum. Indicated for tinea pedis. Inhibits fungal cell growth by inhibiting cytochrome P-450–dependent synthesis of ergosterol, a vital component of fungal cell membranes. Alters fungal cell wall membrane permeability.
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Wax model of kerionlike tinea barbae. Courtesy of the Museum of the Department of Dermatology, University of Medicine, Wroclaw, Poland.
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Tinea capitis; gray patch ringworm. Gray patch refers to the scaling with lack of inflammation, as noted in this patient. Hairs in the involved areas assume a characteristic dull, grayish, discolored appearance and are broken and shorter.
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Typical lesions of kerion celsi on the vertex scalp of a young Chinese boy. Note numerous bright yellow purulent areas on skin surface, surrounded by adjacent edematous, erythematous, alopecic areas. Culture from the lesion grew Trichophyton mentagrophytes. Courtesy of Skin Diseases in Chinese by Yau-Chin Lu, MD. Permission granted by Medicine Today Publishing Co, Taipei, Taiwan, 1981.
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Annular plaque (tinea corporis).
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Tinea favosa of the scalp shows erythematous lesions with pityroid scaling. Some hairs are short and brittle.
Tables
Species |
Natural habitat |
Incidence |
E floccosum |
Humans |
Common |
T rubrum |
Humans |
Very common |
T interdigitale |
Humans |
Very common |
T tonsurans |
Humans |
Common |
Trichophyton violaceum |
Humans |
Less common |
Trichophyton concentricum |
Humans |
Rare |
Trichophyton schoenleinii |
Humans |
Rare |
Trichophyton soudanense |
Humans |
Rare |
Microsporum audouinii |
Humans |
Less common |
Microsporum ferrugineum |
Humans |
Less common |
T mentagrophytes |
Mice, rodents |
Common |
Trichophyton equinum |
Horses |
Rare |
Trichophyton erinacei |
Hedgehogs |
Rare |
Trichophyton verrucosum |
Cattle |
Rare |
M canis |
Cats |
Common |
Microsporum gypseum |
Soil |
Common |
Microsporum nanum |
Soil/pigs |
Rare |
Microsporum cookei |
Soil |
Rare |
