Home Books Fitzpatrick's Dermatology in General Medicine, 8e

Chapter 189. Yeast Infections: Candidiasis, Tinea (Pityriasis) Versicolor, and Malassezia (Pityrosporum) Folliculitis

Roopal V. Kundu; Amit Garg

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Yeast Infections at a Glance

Candidiasis refers to a diverse group of acute and chronic integumentary or disseminated yeast infections, most commonly caused by Candida albicans.
Candida species are the most common cause of fungal infection in immunocompromised persons.
Malassezia yeast, although normal flora in most healthy individuals, cause a wide spectrum of superficial cutaneous disease, including tinea versicolor and Malassezia folliculitis.
Common predisposing factors associated with Candida and Malassezia infection include a warm, humid environment; hyperhidrosis; occlusion of skin and hair follicles; oral contraceptive, antibiotic and systemic corticosteroid use; diabetes mellitus; and immunosuppression.
Potassium hydroxide preparation of skin scrapings demonstrates the characteristic fungal elements that identify Candida and Malassezia.
Multiple topical and systemic agents are effective in treating infection with Candida and Malassezia; however, recurrences are common.

The genus Candida is comprised of a heterogeneous group of over 200 yeast species.1 Candida species are ubiquitous yeast-like fungi that form true hyphae, pseudohyphae, and budding yeasts. Candidiasis (or candidosis) refers to a diverse profile of yeast infections caused by members of the genus Candida, and predominantly by Candida albicans. Candida species are among the most common fungal pathogens to affect humans. While the skin, nails, mucous membranes, and gastrointestinal tract are typical sites of infection, Candida may involve any part of the body. Although considered opportunistic human pathogens, Candida species may also exist as commensal organisms of skin and mucosal membranes of the gastrointestinal, genitourinary, and respiratory tracts.

Epidemiology

Frequency

Candida are usually limited to human and animal hosts, however they have also been recovered from the hospital environment: countertops, air-conditioning vents, floors, respirators, and on medical personnel. Oropharyngeal colonization with Candida is observed in up to 50% of healthy individuals 2 and may also be detected in 40%–65% of normal stool samples. In addition, C. albicans exists as a commensal organism in the vaginal mucosa of 20%–25% of asymptomatic, healthy women3 and up to 30% of healthy pregnant women.4 Vulvovaginal candidiasis (VC) is the second most common cause of vaginitis in women.

Candida species are the most common cause of fungal infection in immunocompromised persons. More than 90% of persons infected with HIV not receiving highly active antiretroviral therapy (HAART) develop oropharyngeal candidiasis and 10% of these patients develop esophageal candidiasis.5–6 Candida species are now the fourth most commonly isolated pathogens from blood cultures in patients with systemic infections.7

Mortality/Morbidity

Most candidal infections are mucocutaneous. While in few cases there may be pronounced effect on morbidity, these infections do not lead to death. However, immunocompromised patients including hospitalized patients, may develop candidemia and disseminated candidiasis which have a 30%–40% mortality rate. In fact, systemic candidiasis causes more case fatalities than any other systemic mycosis.

Sex

Neither ...

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