Cutaneous Fungal Infections
Cutaneous fungal infections are commonly caused by dermatophytes. The prevalent dermatophytic infections in the United States include tinea pedis, tinea corporis, tinea cruris, tinea capitis, and tinea unguium. Persons most susceptible to fungal skin infections include immunodeficient or immunosuppressed patients, obese individuals, patients with impaired circulation, and those who are exposed to prolonged moisture or have poor hygiene. Tinea pedis, tinea corporis, and tinea cruris typically are treated topically, unless the infection is extensive, severe, or recalcitrant. Tinea unguium responds best to oral therapy, and tinea capitis must be treated with oral antifungal therapy, since topical agents cannot penetrate the hair shaft. Treatment may last for several weeks to months, making patient adherence an important factor in therapy selection.
Cutaneous fungal infections are superficial infections typically involving the skin, hair, and nails. Most commonly, these fungal infections are caused by dermatophytes, but they can also be caused by nondermatophyte fungi and yeast (Candida species). The term dermatophyte refers to a fungal organism that causes tinea, a fungal infection. Thus, dermatophytoses are known as tinea infections, which are further classified by the region of the body infected (e.g., tinea pedis, tinea capitis).
Dermatophytoses are limited to the stratum corneum, nails, and hair shafts because they require keratin for growth. The prevalent dermatophytic infections in the United States include tinea pedis (foot), tinea corporis (body), tinea cruris (groin), tinea capitis (scalp), and tinea unguium (nail). In the U.S., there are three dermatophyte genera that cause infections: Microsporum, Epidermophyton, and Trichophyton. Trichophyton is the most prevalent genus, accounting for approximately 80% of dermatophytic infections in the U.S. The most common mode of transmission of dermatophytes is by direct contact with other people (anthropophilic organisms), but transmission also occurs via contact with animals (zoophilic organisms), the soil (geophilic organisms), and fomites. Individuals most susceptible to fungal skin infections include those who are obese, immunodeficient, or immunosuppressed or have impaired circulation. Fungal infections are also more likely to occur with prolonged exposure to sweaty clothes or bedding, poor hygiene, and residence in warm, humid climates.
The classic appearance of a cutaneous tinea infection is a central clearing surrounded by an active border of redness and scaling, which gives rise to the more common name, ringworm. One key point in recognizing a cutaneous fungal infection is the location; tinea infections have no mucosal involvement, since dermatophytes invade only keratinized tissue. Despite having a classic appearance, tinea infections may be similar in appearance to many other derma tologic conditions and are often misdiagnosed and, therefore, mistreated. This article will guide pharmacists to recognize the most common fungal infections, understand the most effective treatment options, and provide counseling for treatment and prevention.
Abstract and Introduction
Abstract
Cutaneous fungal infections are commonly caused by dermatophytes. The prevalent dermatophytic infections in the United States include tinea pedis, tinea corporis, tinea cruris, tinea capitis, and tinea unguium. Persons most susceptible to fungal skin infections include immunodeficient or immunosuppressed patients, obese individuals, patients with impaired circulation, and those who are exposed to prolonged moisture or have poor hygiene. Tinea pedis, tinea corporis, and tinea cruris typically are treated topically, unless the infection is extensive, severe, or recalcitrant. Tinea unguium responds best to oral therapy, and tinea capitis must be treated with oral antifungal therapy, since topical agents cannot penetrate the hair shaft. Treatment may last for several weeks to months, making patient adherence an important factor in therapy selection.
Introduction
Cutaneous fungal infections are superficial infections typically involving the skin, hair, and nails. Most commonly, these fungal infections are caused by dermatophytes, but they can also be caused by nondermatophyte fungi and yeast (Candida species). The term dermatophyte refers to a fungal organism that causes tinea, a fungal infection. Thus, dermatophytoses are known as tinea infections, which are further classified by the region of the body infected (e.g., tinea pedis, tinea capitis).
Dermatophytoses are limited to the stratum corneum, nails, and hair shafts because they require keratin for growth. The prevalent dermatophytic infections in the United States include tinea pedis (foot), tinea corporis (body), tinea cruris (groin), tinea capitis (scalp), and tinea unguium (nail). In the U.S., there are three dermatophyte genera that cause infections: Microsporum, Epidermophyton, and Trichophyton. Trichophyton is the most prevalent genus, accounting for approximately 80% of dermatophytic infections in the U.S. The most common mode of transmission of dermatophytes is by direct contact with other people (anthropophilic organisms), but transmission also occurs via contact with animals (zoophilic organisms), the soil (geophilic organisms), and fomites. Individuals most susceptible to fungal skin infections include those who are obese, immunodeficient, or immunosuppressed or have impaired circulation. Fungal infections are also more likely to occur with prolonged exposure to sweaty clothes or bedding, poor hygiene, and residence in warm, humid climates.
The classic appearance of a cutaneous tinea infection is a central clearing surrounded by an active border of redness and scaling, which gives rise to the more common name, ringworm. One key point in recognizing a cutaneous fungal infection is the location; tinea infections have no mucosal involvement, since dermatophytes invade only keratinized tissue. Despite having a classic appearance, tinea infections may be similar in appearance to many other derma tologic conditions and are often misdiagnosed and, therefore, mistreated. This article will guide pharmacists to recognize the most common fungal infections, understand the most effective treatment options, and provide counseling for treatment and prevention.