Candidiasis refers to infection, commonly of the skin and mucous membranes, less commonly of the gastrointestinal tract, by commensal yeast of the genus Candida.
Candida albicans is a dimorphic yeast. Budding with hyphae or pseudohyphae is seen under microscopy. It’s the most common cause of cutaneous and systemic candidiasis (up to 80% of cases). Candida sp. are found in the oropharynx in half the population and in the vaginal mucosa of up to one third of healthy women. It’s sometimes found on normal skin or skin folds.
Oral candidiasis is also known as “thrush.” It presents as well-demarcated white patches or plaques with underlying erythema on the oral mucosa. The white areas resemble milk curds and contain desquamated epithelial cells, inflammatory cells, fungal elements and food debris. Lesions can ulcerate in severe cases. Variants include acute and chronic atrophic candidiasis. Instead of thick white plaques, there are smooth, shiny, erythematous atrophic plaques. The chronic form is common in denture-wearers, with persistent erythema and edema under denture contacts.
Candidal angular cheilitis is characterized by soreness, maceration and fissuring at the angles of the mouth. It’s especially seen in lip-lickers, and elderly patients with drooping skin at the angles of the mouth. Not all cases are due to yeast — consider bacterial superinfection, contact dermatitis, nutritional deficiencies.
Patients should apply a barrier moisturizer to the lips frequently. Try petroleum jelly or zinc oxide ointments, especially before bed and meals. Topical antifungals that are effective against yeasts are the mainstay of therapy. Clotrimazole and nystatin creams are good options. If these are ineffective, oral antifungals, e.g. fluconazole, should be considered.
Vulvovaginal candidiasis is very common, affecting up to three quarters of women at some point. The main risk factor is a recent course of oral antibiotics. Oral antibiotics decrease the normal flora — especially lactobacilli — and allow for overgrowth of Candida sp. Patients often complain of itching, burning, with thick white discharge. On examination of the mucosa, there are white plaques with underlying erythema. There can be local edema. Recurrent vulvovaginal candidiasis refers to four or more episodes per year.
Balanitis refers to inflammation of the glans penis. In men, one third of infectious balanitis is caused by Candida sp. Multiple, erythematous papules and small pustules are seen on the glans. Lesions can spread to the inguinal folds and scrotum. It tends to be more severe — with ulceration — in immunosuppressed patients.
Intertrigo refers to erythema of the skin folds. Candidal infection is a common cause. Candida sp. favours warm moist areas and common sites include the axillae, inframmary folds, abdominal folds, inguinal folds and webspaces (erosio interdigitalis blastomycetica). There’s often pruritus, with maceration and erythema, as well as satellite lesions of papules and pustules.
Candidal diaper dermatitis
Treatment of cutaneous candidiasis
Chronic mucocutaneous candidiasis
This is a group of disorders characterized by deficient candidal immunity and recurrent candidal infections.
Chronic candidiasis with endocrinopathy
If other infections, consider evaluations of the immune system
John Kraft, MD, is in his third year of the Dermatology Residency Program at the University of Toronto.
Charles Lynde, MD, FRCP(C) is an assistant professor of dermatology at the University of Toronto.