Candidiasis (Mucocutaneous)


ByDenise M. Aaron, MD, Dartmouth Geisel School of Medicine
Reviewed/Revised Sept 2023
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Candidiasis is skin and mucous membrane infection with Candida species, most commonly Candida albicans. Infections can occur anywhere and are most common in skinfolds, digital web spaces, genitals, cuticles, and oral mucosa. Symptoms and signs vary by site. Diagnosis is by clinical appearance and/or potassium hydroxide wet mount of skin scrapings. Treatment is with drying agents and antifungals.

Most candidal infections are of the skin and mucous membranes, but invasive candidiasis is common among patients who are immunosuppressed and can be life threatening.

Systemic candidiasis is discussed in Fungi. Vulvovaginal candidiasis is discussed in Candidal Vaginitis.

Etiology of Mucocutaneous Candidiasis

Potentially pathogenic fungi include dermatophytes and yeast. Candida is a group of about 150 yeast species. C. albicans is responsible for about 70 to 80% of all candidal infections. Other significant species include C. glabrata, C. tropicalis, C. krusei, and C. dubliniensis.

Candida is a ubiquitous yeast that resides harmlessly on skin and mucous membranes until dampness, heat, and impaired local and systemic defenses provide a fertile environment for it to grow.

Risk factors for candidiasis include

  • Hot weather

  • Restrictive clothing

  • Poor hygiene

  • Infrequent diaper or undergarment changes in children and older adults

  • Altered flora resulting from antibiotic therapy

  • Inflammatory diseases (eg, psoriasis) that occur in skinfolds

  • Immunosuppression resulting from corticosteroids and immunosuppressive medications, pregnancy, diabetes, other endocrinopathies (eg, Cushing disease, hypoadrenalism, hypothyroidism), blood dyscrasias, HIV/AIDS, or T-cell defects

Candidiasis occurs most commonly in intertriginous areas such as the axillae, groin, and gluteal folds (eg, diaper rash), in digital web spaces, on the glans penis, and beneath the breasts. Vulvovaginal candidiasis is common among women. Candidal nail infections and paronychia may develop after improperly done manicures and in kitchen workers and others whose hands are continually exposed to water (see Onychomycosis). In people with obesity, candidal infections may occur beneath the pannus (abdominal fold). Oropharyngeal candidiasis is a common sign of local or systemic immunosuppression.

Chronic mucocutaneous candidiasis typically affects the nails, skin, and oropharynx. Patients have cutaneous anergy to Candida, absent proliferative responses to Candida antigen (but normal proliferative responses to mitogens), and an intact antibody response to Candida and other antigens. They also have impaired T-cell–mediated immunity. Chronic mucocutaneous candidiasis may occur as an autosomal recessive illness associated with hypoparathyroidism and Addison disease (Candida-endocrinopathy syndrome).

Symptoms and Signs of Mucocutaneous Candidiasis

Intertriginous infections manifest as pruritic, well-demarcated, erythematous patches of varying size and shape; erythema may be difficult to detect in darker-skinned patients. Primary patches may have adjacent satellite papules and pustules.

Perianal candidiasis produces white maceration and pruritus ani.

Vulvovaginal candidiasis causes pruritus and discharge (see Candidal Vaginitis).

Vulvovaginal Candidiasis
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Characteristic findings in vulvovaginal candidiasis include a white discharge and vulvar erythema.

Candidal nail infections can affect the nail plate, edges of the nail, or both. Candidal infection is a frequent cause of chronic paronychia, which manifests as painful red periungual swelling. Subungual infections are characterized by distal separation of one or several fingernails (onycholysis), with white or yellow discoloration of the subungual area.

Candidiasis (Nail Infection)
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Candidal nail infections can involve the full thickness of the nail plate (onychomycosis), the edges of the nail (paronychia), or both.
Image courtesy of CDC/Sherry Brinkman via the Public Health Image Library of the Centers for Disease Control and Prevention.

Oropharyngeal candidiasis causes white plaques on oral mucous membranes that may bleed when scraped (see Interpretation of findings).

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Creamy white patches are seen inside the mouth and may bleed when scraped off. This finding is typical of thrush, which is caused by infection with Candida.
Image provided by Thomas Habif, MD.

Perlèche is candidiasis at the corners of the mouth, which causes cracks and tiny fissures. It may stem from chronic lip licking, thumb sucking, ill-fitting dentures, or other conditions that make the corners of the mouth moist enough that yeast can grow.

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Perlèche is candidiasis at the corners of the mouth, causing tiny cracks and fissures.
© Springer Science+Business Media

Chronic mucocutaneous candidiasis is characterized by red, pustular, crusted, and thickened plaques resembling psoriasis, especially on the nose and forehead, and is invariably associated with chronic oral candidiasis.

Candidiasis (Chronic Mucocutaneous)
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Patients with chronic mucocutaneous candidiasis are anergic to Candida. They develop red, pustular, thickened, crusted plaques that may appear psoriatic. Plaques may appear on the nose, forehead, and elsewhere.
Image courtesy of © 2005.

Diagnosis of Mucocutaneous Candidiasis

  • Clinical appearance

  • Potassium hydroxide wet mounts

Diagnosis of mucocutaneous candidiasis is based on clinical appearance and identification of yeast and pseudohyphae in potassium hydroxide wet mounts of scrapings from a lesion.

Positive culture alone is usually meaningless because Candida is omnipresent.

Treatment of Mucocutaneous Candidiasis

  • Sometimes drying agents

  • Topical or oral antifungals

Intertriginous infection is treated with drying agents as needed (eg, Burow solution compresses applied for 15 to 20 minutes for oozing lesions) and topical antifungals (see table Options for Treatment of Superficial Fungal Infections


Candidal diaper rash

Candidal paronychia is treated by protecting the area from wetness and giving topical or oral antifungals. These infections are often resistant to treatment. Thymol 4% in alcohol applied to the affected area 2 times a day is often helpful.

Oral candidiasis

Chronic mucocutaneous candidiasis

Key Points

  • Candida are normal skin flora that can become infective under certain conditions (eg, excessive moisture, alteration of normal flora, host immunosuppression).

  • Consider candidiasis with erythematous, scaling, pruritic patches in intertriginous areas and with lesions in the mucous membranes, around the nails, or at the corners of the mouth.

  • If clinical appearance is not diagnostic, try to identify yeast and pseudohyphae in potassium hydroxide wet mounts of scrapings from a lesion.

  • Treat most intertriginous candidiasis with a drying agent and a topical antifungal.

  • Treat most diaper rash with frequent changes of absorbent disposable diapers and an imidazole cream.

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