Dermatomycosis
Dermatomycosis is a superficial fungal infection that affects the skin and its appendages, such as hair and nails, caused by dermatophytes, yeasts, and other fungi. Common forms of dermatomycosis include tinea barbae (ringworm of the beard), tinea capitis (ringworm of the scalp), tinea corporis (ringworm of the body), tinea cruris (jock itch), tinea pedis (athlete's foot), and tinea unguium (nail fungus). The primary fungi responsible for these infections belong to the genera Microsporum, Epidermophyton, and Trichophyton, alongside Candida albicans, which can proliferate under certain health conditions or disruptions in normal flora.
While dermatomycosis can occur in healthy individuals, those who are immunocompromised or in poor health are at a higher risk of severe and recurrent infections. Symptoms vary based on the infection type, typically involving inflammation, itching, and lesions that can range from mild scaling to deep, pustular formations. Diagnosis is confirmed through microscopic examination of scrapings from affected areas. Treatment often involves topical antifungal medications, systemic antifungal treatments, and occasionally antibiotics for secondary bacterial infections. Preventive measures focus on maintaining skin hygiene and avoiding exposure to contaminated environments.
Dermatomycosis
- ANATOMY OR SYSTEM AFFECTED: Feet, genitalia, hair, head, nails, scalp, skin
Definition
Dermatomycosis is a superficial fungal infection of the skin and its appendages (hair and nails) caused by dermatophytes, yeasts, and other fungi. The condition includes candidal (yeast) infections and skin disorders such as tinea barbae (ringworm of the beard), tinea capitis (ringworm of the scalp and hair), tinea corporis (ringworm of the body), tinea cruris (jock itch, or ringworm of the groin), tinea pedis (ringworm of the foot, or athlete’s foot), and tinea unguium (ringworm of the nail).
Causes
Fungi are a large group of eukaryotic microorganisms that include molds and yeasts. Approximately four hundred species have been found to cause disease in humans, forty of which are common causes of skin disease. The genera of fungi that most commonly cause dermatomycosis are Microsporum, Epidermophyton, and Trichophyton. These species, which are also known as dermatophytes, colonize the outer layer of the skin and feed on keratinized material.
In addition to dermatophytes, yeasts such as Candida albicans are also common causes of dermatomycosis. C. albicans is part of the normal flora of the skin, vagina, and gastrointestinal tract. However, ill health, impaired immunity, and antibiotic treatment can disrupt the normal balance of bacterial flora, triggering the yeast to multiply and cause disease.
Risk Factors
Dermatomycosis can occur in healthy persons. However, immunocompromised persons, such as those with human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome (AIDS), and those in poor health are at increased risk of severe, chronic, and recurrent dermatomycosis. Persons taking antibiotics may also be at increased risk.
Symptoms
The signs and symptoms of dermatomycosis vary depending on the type and location of the infection. Most types of dermatomycosis cause symptoms of inflammation and itching.
Tinea barbae causes mild superficial lesions resembling tinea corporis and leads to severe lesions characterized by deep, pustular folliculitis. Tinea capitis causes scaly erythematous lesions and alopecia (hair loss) that can become severely inflamed; this leads to the formation of keloids and scarring with permanent alopecia. Tinea corporis causes lesions ranging from simple scaling to scaling with erythema and vesicles to deep granulomata.
Tinea cruris causes lesions that are usually sharply demarcated, with a raised erythematous margin and thin, dry epidermal scaling. Tinea pedis causes lesions ranging from mild, chronic, and scaling to acute, exfoliative, pustular, and bullous.
Tinea unguium can cause an infection restricted to patches or pits on the nail's surface, or an invasive infection involving the lateral or distal edges of the nail. The infection then spreads beneath the nail plate.
Screening and Diagnosis
The diagnosis of dermatomycosis is made by finding characteristic hyphae or spores on microscopic analysis of skin, nail, and scalp scrapings. Cultures are also used to definitively identify the responsible species of fungus.
Treatment and Therapy
The treatment of dermatomycosis may include topical antifungal medications such as clotrimazole, butenafine, and miconazole and systemic medications such as fluconazole, griseofulvin, terbinafine, and itraconazole. Topical antifungal medications, including luliconazole, efinaconazole, and tavaborole are newer and more effective treatment methods. Oral antifungal medications, such as posaconazole and voriconazole, may also be used. Antibiotics may also be necessary to treat secondary bacterial infections that occur as a result of scratching.
Prevention and Outcomes
Dermatophytes are transmitted by direct contact with infected human or animal hosts, or by direct or indirect contact with contaminated exfoliated skin or hair in the environment. Thus, preventive measures include reducing or eliminating exposure to sources of disease transmission. In addition, one can help prevent dermatomycosis by keeping skin clean and dry, receiving immediate and concurrent treatment to prevent spreading, and taking prophylactic medicine to prevent recurrence.
Bibliography
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Richardson, Malcolm D., and Elizabeth M. Johnson. The Pocket Guide to Fungal Infection. 2d ed., Malden, Mass.: Blackwell, 2006.
"Ringworm of the Scalp." MedlinePlus, 18 Nov. 2022, medlineplus.gov/ency/article/000878.htm. Accessed 27 Sept. 2024.
"Toenail Fungus (Onychomycosis/Tinea Unguium): Symptoms & Causes." Cleveland Clinic, 11 Aug. 2022, my.clevelandclinic.org/health/diseases/11303-toenail-fungus. Accessed 27 Sept. 2024.
Wolff, Klaus, and Richard Allen Johnson. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. 6th ed., New York: McGraw-Hill Medical, 2009.