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eMedicine Journal
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Emergency Medicine
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Infectious Diseases
Tinea Synonyms, Key Words, and Related Terms: tinea, dermatophytes, dermatophytosis, Epidermophyton, Microsporum, Trichophyton, tinea capitis, tinea corporis, tinea manuum, tinea pedis, tinea cruris, tinea barbae, tinea faciale, tinea unguium, onychomycosis, ringworm, fungal infection, Trichophyton rubrum, Trichophyton tonsurans, Trichophyton interdigitale, Trichophyton mentagrophytes, Microsporum canis, Epidermophyton floccosum |
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| AUTHOR INFORMATION | Section 1 of 10 |
Authored by Jerome FX Naradzay, MD, FACEP, Emergency Services Medical Director, Department of Emergency Medicine, Maria Parham Medical Center
Coauthored by Nelly Rubeiz, MD, Consulting Staff, Department of Dermatology, American University of Beirut Medical Center; Associate Professor, Department of Dermatology, American University of Beirut, Lebanon; Zeina Tannous, MD, Consulting Staff, Department of Dermatology, Massachusetts General Hospital, Harvard Medical School
Jerome FX Naradzay, MD, FACEP, is a member of the following medical societies: American College of Emergency Physicians, and Society for Academic Emergency Medicine
Edited by Theodore Gaeta, DO, MPH, Residency Director, Clinical Associate Professor of Emergency Medicine in Medicine, Department of Emergency Medicine, New York Methodist Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Eddy Lang, MDCM, CCFP (EM), CSPQ, Assistant Professor, Department of Family Medicine, McGill University; Consulting Staff, Department of Emergency Medicine, The Sir Mortimer B Davis-Jewish General Hospital; John Halamka, MD, Chief Information Officer, CareGroup Healthcare System, Assistant Professor of Medicine, Department of Emergency Medicine, Beth Israel Deaconess Medical Center; Assistant Professor of Medicine, Harvard Medical School; and Charles V Pollack, Jr, MD, MA, FACEP, Professor, Department of Emergency Medicine, University of Pennsylvania College of Medicine; Chairman, Department of Emergency Medicine, Pennsylvania Hospital
| Author's Email: | Jerome FX Naradzay, MD, FACEP | |
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| Editor's Email: | Theodore Gaeta, DO, MPH |
eMedicine Journal, November 15 2006, VOLUME 7,
Number 11
| INTRODUCTION | Section 2 of 10 |
Background: The dermatophytes are a group of fungi (ringworm) that invade the dead keratin of skin, hair, and nails. Several species of dermatophytes infect humans; these belong to the Epidermophyton, Microsporum, and Trichophyton genera.
Dermatophytosis (tinea) is a fungal infection caused by dermatophytes. The infection may spread from person to person (anthropophilic), animal to person (zoophilic), or soil to person (geophilic). The most common of these organisms are Trichophyton rubrum, Trichophyton tonsurans, Trichophyton interdigitale and/or Trichophyton mentagrophytes, Microsporum canis, and Epidermophyton floccosum.
Pathophysiology: Dermatophytes have the ability to invade keratinized tissue (eg, hair, nails, any area of the skin) but are restricted to the dead cornified layer of the epidermis. Humid or moist skin provides a very favorable environment for the establishment of fungal infection. Clinically, tinea infections are classified according to the body region involved.
Frequency:
Tinea capitis (ringworm of the head) is the most common dermatophytosis of childhood with an increasing incidence worldwide.
Onychomycosis is a common problem, especially in adults. In a survey in the US, the prevalence of onychomycosis was approximately 3% in males and 1.4% in females. In a sample of North American children, 0.44% had onychomycosis.
Mortality/Morbidity:
Race: Fungal infection affects all races; however, the prevalence of organisms varies by country.
Sex: Both sexes are affected by fungal infection. Tinea cruris is much more common in males because of the male anatomy, which allows moisture to accumulate in the crural folds.
Age:
| CLINICAL | Section 3 of 10 |
History:
Physical: At physical examination, the various types of tinea may have different findings, as follows:
Causes: The various tinea infections are caused chiefly by species of the genera Microsporum, Trichophyton, and Epidermophyton. Risk factors include the following:
| DIFFERENTIALS | Section 4 of 10 |
Candidiasis
Cellulitis
Dermatitis, Atopic
Dermatitis, Contact
Erysipelas
Impetigo
Psoriasis
Vulvovaginitis
Other Problems to be Considered:
Alopecia areata
Atopic eczema
Erythrasma
Intertrigo
Seborrheic dermatitis
| WORKUP | Section 5 of 10 |
Lab Studies:
Other Tests:
| TREATMENT | Section 6 of 10 |
Emergency Department Care: Certain forms of tinea easily can be identified and treated with antifungals in the ED. However, the diagnosis should probably be confirmed with a potassium hydroxide smear and/or cultures.
Consultations: A dermatologist may be consulted.
| MEDICATION | Section 7 of 10 |
Fungal infections may be treated with topical agents (ie, creams, lotions, solutions, powders, sprays) or with oral antifungals in extensive or recalcitrant disease. Topical therapy is ineffective in treating tinea of the hair and nails. 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; these have greatly improved the outlook (especially for patients with fungal toenail infection).
Drug Category: Antifungals -- The optimal duration of topical therapy for dermatophytic infections of the skin has never been established. 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.
| Drug Name | Ketoconazole 2% cream (Nizoral) -- 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. |
|---|---|
| Adult Dose | Rub gently into affected area qd or bid for 2-4 wk |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | None reported |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | If sensitivity or irritation develops, discontinue use; for external use only; avoid contact with eyes |
| Drug Name | Clotrimazole 1% cream or lotion (Lotrimin, Mycelex) -- 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. |
|---|---|
| Adult Dose | Gently massage into affected and surrounding skin areas bid for 2-6 wk |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | None reported |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | If sensitivity or chemical irritation occurs, discontinue use; use only externally; avoid contact with eyes |
| Drug Name | Econazole 1% cream or lotion (Spectazole) -- Effective in cutaneous infections. Interferes with RNA and protein synthesis and metabolism. Disrupts fungal cell-wall membrane permeability, causing fungal cell death. |
|---|---|
| Adult Dose | Apply sparingly over affected areas qd for 2-6 wk |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | None reported |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | If sensitivity or irritation develops, discontinue use; for external use only; avoid contact with eyes |
| Drug Name | Miconazole 2% cream (Monistat, Daktarin) -- 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. |
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| Adult Dose | Cream and lotion: Cover affected areas bid for 2-6 wk Powder: Spray or sprinkle liberally over affected area bid |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | None reported |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | If sensitivity or chemical irritation occurs, discontinue use; use only externally; avoid contact with eyes |
| Drug Name | 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. |
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| Adult Dose | Terbinafine tab Tinea cruris, tinea corporis: 250 mg/d PO for 2-4 wk Tinea pedis: 250 mg/d PO for 2-6 wk Tinea capitis: 250 mg/d PO for 4 wk Fingernail infection: 250 mg/d PO for 6-8 wk Toenail infection: 250 mg/d PO for 3-4 mo Terbinafine 1% cream Tinea corporis, tinea cruris: Apply to affected area qd for 1-4 wk Tinea pedis: Apply to affected area bid for 1-4 wk |
| Pediatric Dose | Terbinafine tab, treatment duration similar to that in adults 12-20 kg: 62.5 mg/d PO 20-40 kg: 125 mg/d PO >40 kg: 250 mg/d PO Terbinafine 1% cream <12 years: Not established >12 years: Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | Coadministration of PO form may increase cyclosporine clearance; rifampin and phenobarbital may decrease terbinafine level; cimetidine may decrease terbinafine clearance |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Discontinue use if chemical irritation or signs of hepatobiliary dysfunction develop; topical dosage form is for external use only; avoid contact with eyes |
| Drug Name | 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. |
|---|---|
| Adult Dose | Cream: Gently massage sufficient quantity into affected area and surrounding skin qd for 2-4 wk Gel: Gently massage sufficient quantity into affected and surrounding skin areas bid for 2-4 wk |
| Pediatric Dose | Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | None reported |
| Pregnancy | B - Usually safe but benefits must outweigh the risks. |
| Precautions | Discontinue use if sensitivity or chemical irritation occurs; for external use only; avoid contact with eyes |
| Drug Name | Griseofulvin (Gris-PEG, Grifulvin V, Fulvicin, Griseofulvin) -- 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. |
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| Adult Dose | Tinea corporis, tinea cruris, and tinea capitis: 500 mg microsize (330-375 mg ultramicrosize) PO in single or divided daily doses for 2-6 wk Tinea pedis, tinea unguium: 0.75-1 g microsize (660-750 mg ultramicrosize) PO in single or divided doses for 2-6 wk |
| Pediatric Dose | 11 mg microsize/kg/d (5 mg/lb/d) PO or 7.3 mg ultramicrosize/kg/d (3.3 mg/lb/d) PO |
| Contraindications | Documented hypersensitivity |
| Interactions | May decrease hypoprothrombinemic activity of warfarin; patients may require a dosage adjustment; oral contraceptives may lose effectiveness when administered concurrently, possibly leading to breakthrough bleeding, amenorrhea, or unintended pregnancy; may reduce effects of cyclosporine; may decrease serum salicylate concentrations; barbiturates may decrease serum levels |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | For prolonged therapy, observe patients closely; monitor renal, hepatic, and hematopoietic function regularly; lupus-like syndromes or exacerbation of lupus erythematosus may occur; photosensitivity may occur; patients should take protective measures against exposure to UV light or sunlight |
| Drug Name | 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. |
|---|---|
| Adult Dose | Tinea corporis, tinea cruris: 100 mg/d PO 2 wk or 200 mg/d PO for 1 wk Tinea pedis: 200 mg bid PO for 1 wk Toenail infection: 200 mg bid PO 1 for wk, given 1 wk/mo for 3-4 mo Fingernail infection: 200 mg PO bid for 1 wk, given 1 wk/mo for 1-2 mo Tinea capitis: 5 mg/kg/d (max dose 100 mg/d) PO for 2-4 wk |
| Pediatric Dose | Not established Suggested dose in children 3-16 years: 100 mg/d PO for 1 wk |
| Contraindications | Documented hypersensitivity |
| Interactions | Antacids may reduce absorption; edema may occur with coadministration of calcium-channel blockers (eg, amlodipine, nifedipine); hypoglycemia may occur with sulfonylureas; may increase tacrolimus and cyclosporine plasma concentrations when high doses are used; rhabdomyolysis may occur with coadministration of HMG-CoA reductase inhibitors (lovastatin or simvastatin); coadministration with cisapride can cause cardiac rhythm abnormalities and death; may increase digoxin levels; coadministration may increase plasma levels of midazolam or triazolam; phenytoin and rifampin may reduce itraconazole levels (phenytoin metabolism may be altered) |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Caution in hepatic insufficiencies; absorption impaired when gastric acidity is decreased; discontinue if neuropathy attributable to itraconazole occurs |
| Drug Name | 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. |
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| Adult Dose | Tinea corporis, tinea cruris: 150 mg/wk PO for 2-4 wk Tinea pedis: 150 mg/wk PO for as long as 6 wk Toenail infection: 150 mg/wk PO for 6-12 mo Fingernail infection: 150 mg/wk PO for 3-6 mo |
| Pediatric Dose | Not established |
| Contraindications | Documented hypersensitivity |
| Interactions | Levels may increase with hydrochlorothiazides; levels may decrease with chronic coadministration of rifampin; coadministration may decrease phenytoin concentrations; may increase concentrations of theophylline, tolbutamide, glyburide, and glipizide; effects of anticoagulants may increase with coadministration; increases in cyclosporine concentrations may occur when administered concurrently |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | Monitor patient closely if rashes develop, and discontinue drug if lesions progress; may cause clinical hepatitis, cholestasis, and fulminant hepatic failure (including death) with underlying medical conditions such as AIDS, malignancy, or multiple concomitant medications; not recommended for breastfeeding women |
| Drug Name | Sertaconazole nitrate cream (Ertaczo) -- Topical imidazole antifungal active against T rubrum, T mentagrophytes, E floccosum. Indicated for tinea pedis. |
|---|---|
| Adult Dose | Apply topically bid to clean, dry skin between the toes and the immediate surrounding healthy skin |
| Pediatric Dose | <12 years: Not established >12 years: Administer as in adults |
| Contraindications | Documented hypersensitivity |
| Interactions | None reported |
| Pregnancy | C - Safety for use during pregnancy has not been established. |
| Precautions | For topical use only; may cause dermatitis, dry skin, burning sensation, pruritus, hyperpigmentation, desquamation, or skin tenderness |
| FOLLOW-UP | Section 8 of 10 |
Deterrence/Prevention:
Complications:
Prognosis:
Patient Education:
| TEST QUESTIONS | Section 9 of 10 |
CME Question 1: Which of the following should be considered when choosing drug therapy for fungal toenail infection?
A: Oral griseofulvin
B: Causative agent, likelihood of patient compliance, medication accessibility, and cost of therapy including medication, lab test, and follow-up requirements
C: Topical miconazole
D: Topical ketoconazole
E: Pulse therapy with a topical and oral agent
The correct answer is B: The practitioner should consider the patient`s resources, likelihood of follow-up to monitor therapeutic efficacy and side effects when more than one medication is available for therapy. The practitioner must include the patient about the financial impact of noncompliance as well as the cost of compliance. Sending a patient to a pharmacy to get a prescription without discussing or appreciating the cost of therapy could contribute to noncompliance. Successful educational interventions can improve compliance with treatment goals.
CME Question 2: A child has a patch of hair loss that is associated with scales. What is the most likely diagnosis?
A: Alopecia areata
B: Pediculosis capitis
C: Tinea capitis
D: Psoriasis
E: Impetigo
The correct answer is C: Alopecia areata causes patchy hair loss; however, the skin surface remains intact without scales. Psoriasis is scaly but rarely leads to hair loss. Pediculosis capitis does not cause hair loss. Impetigo results in yellowish (pus) crust.
Pearl Question 1 (T/F): Tinea cruris is best treated with a topical allylamine or an azole antifungal.
The correct answer is True: Multiple randomized controlled trials support treating tinea cruris with a topical allylamine (naftifine and terbinafine) or an azole antifungal (clotrimazole, econazole, ketoconazole, oxiconazole, miconazole, and sulconazole).
Pearl Question 2 (T/F): For tinea capitis, a safe and effective alternative to griseofulvin is itraconazole.
The correct answer is True: Griseofulvin has historically been considered the standard treatment of tinea capitis; however, recent studies support the efficacy and safety of itraconazole therapy.
Pearl Question 3 (T/F): Combination therapy of oral terbinafine and ciclopirox nail lacquer is a safe and more effective treatment for onychomycosis.
The correct answer is True: Combination therapy of oral terbinafine and ciclopirox nail lacquer is a safe and more effective treatment for onychomycosis than terbinafine alone, especially in younger patients and in shorter-duration onychomycosis.
Pearl Question 4 (T/F): Scalp skin is unique on the body due to the density of hair follicles and high rate of sebum production.
The correct answer is True: Scalp skin is unique on the body due to the density of hair follicles and high rate of sebum production. These features make it susceptible to superficial mycotic conditions (dandruff, seborrheic dermatitis, and tinea capitis), parasitic infestation (pediculosis capitis), and inflammatory conditions (psoriasis).
| BIBLIOGRAPHY | Section 10 of 10 |
| NOTE: |
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| Medicine is a constantly changing science and not all therapies are clearly established. New research changes drug and treatment therapies daily. The authors, editors, and publisher of this journal have used their best efforts to provide information that is up-to-date and accurate and is generally accepted within medical standards at the time of publication. However, as medical science is constantly changing and human error is always possible, the authors, editors, and publisher or any other party involved with the publication of this article do not warrant the information in this article is accurate or complete, nor are they responsible for omissions or errors in the article or for the results of using this information. The reader should confirm the information in this article from other sources prior to use. In particular, all drug doses, indications, and contraindications should be confirmed in the package insert. FULL DISCLAIMER |
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