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.

Clinical presentations

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.

Treatment

• Nystatin suspension (400,000-600,000 units) 4x daily
• If recurrent, consider oral azole therapy
• Be aware of mimickers! Consider a biopsy in resistant cases to rule out malignancy — squamous cell carcinoma — or inflammatory/bullous dermatoses — e.g. lichen planus, pemphigus

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.

Treatment

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.

Treatment

• Consider topical clotrimazole as a first line agent. It often resolves after one week
• Oral agents — fluconazole, itraconazole — are reserved for challenging cases. Prophylactic regimens can be used for recurrent cases such as fluconazole, 150 mg po weekly

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.

Treatment

• Topical clotrimazole cream
• Fluconazole 150 mg po x 1 dose

Cutaneous candidiasis

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

• Occlusion with wet diapers allows yeast from GI tract to colonize the skin, around the anus and spreading to the inguinal creases.

Candidal paronychia

• Exacerbated by wet-work
  • cleaners, fishermen, cooks, bakers, hairstylists
• Inflammation of paronychia with cuticle retraction
• Treatment: avoid wet work, topical antifungal solution, or oral azole

Candida miliaria

• Small erythematous papules and pustules on the backs of bedridden patients.

Treatment of cutaneous candidiasis

• topical antifungal creams
• usually twice daily for 1 week (e.g. clotrimazole 1% cream, ciclopirox olamine 1% cream, ketoconazole 2% cream)
• oral azole therapy, if severe.

Chronic mucocutaneous candidiasis

This is a group of disorders characterized by deficient candidal immunity and recurrent candidal infections.

Chronic candidiasis with endocrinopathy

• Autosomal recessive
• Associated with a variety of endocrinopathies
  • Hypoparathyroidism
  • hypoadrenalism
  • Suspect with recurrent candidal infection in early childhood, usually before age 5, especially in the oral and diaper areas

Treatment

• oral azole antifungal agents
• annual endocrine evaluation

If other infections, consider evaluations of the immune system

• CBC and differential
• HIV serology
• Immunoglobulin levels
• TSH
• Fasting blood glucose
• Serum iron and ferritin
• Calcium
• Parathyroid hormone
• AM cortisol
• Chest x-ray