Infectious Disease · Fungal Infections
The facts most likely to be tested
Oral candidiasis presents as creamy white, curd-like plaques on the buccal mucosa, tongue, or oropharynx that scrape off to reveal an erythematous, friable base.
The causative organism is the dimorphic fungus Candida albicans, which is a normal commensal of the human oral flora.
Diagnosis is primarily clinical, but a KOH preparation showing pseudohyphae and budding yeast confirms the presence of the fungus.
The first-line treatment for mild or localized oral candidiasis is topical nystatin suspension or clotrimazole troches.
Systemic therapy with oral fluconazole is indicated for patients with esophageal involvement, severe disease, or those who are immunocompromised.
New-onset oral thrush in an otherwise healthy adult should prompt screening for HIV/AIDS or diabetes mellitus.
The presence of odynophagia or retrosternal chest pain in a patient with oral thrush is highly suggestive of Candida esophagitis, an AIDS-defining illness.
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A 32-year-old male presents to the clinic complaining of a persistent 'fuzzy' sensation in his mouth and difficulty swallowing for the past week. Physical examination reveals creamy white plaques on the tongue and soft palate that scrape off with a tongue depressor, leaving an erythematous, bleeding base. The patient reports a 15-pound unintentional weight loss over the last three months and a history of unprotected sexual encounters. He has no history of recent antibiotic use or corticosteroid inhaler use.
What is the most appropriate next step in the management of this patient?
HIV antibody/antigen combination immunoassay
The patient presents with classic oral thrush and constitutional symptoms (weight loss) suggestive of an underlying immunodeficiency; therefore, screening for HIV is the highest priority.
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High yield triage
Etiology / Epidemiology
Opportunistic infection by Candida albicans; common in immunocompromised patients, inhaled corticosteroid users, and antibiotic therapy.
Clinical Manifestations
Presents as white, curd-like plaques that scrape off, leaving an erythematous, bleeding base.
Diagnosis
Clinical diagnosis; KOH preparation showing pseudohyphae and budding yeast is the gold standard.
Treatment
Nystatin swish and swallow is first-line; avoid systemic azoles in pregnancy.
Prognosis
Generally self-limiting with treatment; esophageal candidiasis is an AIDS-defining illness.
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Epidemiology & Etiology
Caused by overgrowth of Candida albicans, a commensal fungus. Primary risk factors include HIV/AIDS, diabetes mellitus, and prolonged broad-spectrum antibiotic use. Patients using inhaled corticosteroids without a spacer are at high risk due to local immunosuppression.
Pertinent Anatomy
Infection typically involves the buccal mucosa, tongue, and palate. Involvement of the esophagus indicates severe systemic immunosuppression or advanced AIDS.
Pathophysiology
Disruption of the oral microbiome or host immune surveillance allows commensal yeast to transition into a pathogenic state. The organism forms pseudohyphae that invade the superficial epithelial layers. This invasion triggers an inflammatory response, resulting in the characteristic white pseudomembranous exudate.
Clinical Manifestations
Patients present with white, curd-like plaques on the oral mucosa. A key diagnostic feature is that these plaques scrape off with a tongue depressor, revealing an erythematous, bleeding base. Odynophagia or dysphagia suggests esophageal involvement, which is a red flag for systemic disease.
Diagnosis
Diagnosis is primarily clinical. If uncertain, a KOH preparation of the scrapings is the gold standard, revealing pseudohyphae and budding yeast. A biopsy is rarely required unless the lesion is refractory to treatment.
Treatment
First-line therapy is nystatin swish and swallow or clotrimazole troches. For refractory cases or esophageal involvement, fluconazole is the treatment of choice. Fluconazole is teratogenic and should be avoided in pregnancy.
Prognosis
Most cases resolve quickly with topical therapy. Recurrent thrush in a young, healthy adult warrants testing for HIV or diabetes. Esophageal candidiasis is an AIDS-defining illness and requires systemic antifungal therapy.
Differential Diagnosis
Oral Leukoplakia: white patches that do not scrape off
Oral Lichen Planus: Wickham striae (lacy white lines)
Geographic Tongue: migratory erythematous patches
Diphtheria: gray pseudomembrane that bleeds when scraped
Chemical Burn: history of caustic exposure