What are the clinical manifestations and treatment options for thrush on the tongue in an immunocompromised adult?

Oral Thrush (Oropharyngeal Candidiasis) on the Tongue

Oral thrush on the tongue presents as painless, creamy white, plaque-like lesions that can be easily scraped off with a tongue depressor, or less commonly as erythematous red patches without white plaques diffusely on the tongue surface. 1

Clinical Presentations

Pseudomembranous Form (Classic Thrush)

• Creamy white, plaque-like lesions appear on the tongue surface, buccal mucosa, or oropharyngeal mucosa 1
• Key distinguishing feature: Lesions can be easily scraped off with a tongue depressor or other instrument, which differentiates them from oral hairy leukoplakia 1
• Typically painless in presentation 1

Erythematous Form

• Red patches without white plaques visible diffusely on the tongue or on the anterior/posterior upper palate 1
• This form is predictive of progressive immunodeficiency in HIV-infected patients 1

Angular Cheilitis

• Inflammation and cracking at the corners of the mouth, occasionally caused by Candida 1, 2

Epidemiology and Risk Factors in Immunocompromised Adults

• Most commonly occurs with CD4+ T lymphocyte counts <200 cells/µL in HIV-infected patients 1
• Candida albicans is the predominant causative organism, found in oral cavities of up to two-thirds of healthy individuals 1, 3
• Fluconazole resistance develops predominantly from repeated and prolonged azole exposure, particularly in profoundly immunosuppressed patients 1
• Non-albicans species (particularly C. glabrata and C. krusei) emerge as causes of refractory disease in advanced immunosuppression 1

Diagnosis

Clinical Diagnosis

• Diagnosis is usually clinical based on the appearance of lesions 1
• The ability to scrape off superficial whitish plaques distinguishes thrush from oral hairy leukoplakia 1

Laboratory Confirmation (When Required)

• KOH preparation of scrapings for microscopic examination demonstrates yeast forms 1
• Culture of clinical material identifies the specific Candida species present 1

Important Caveat

• If ulcers are present without white plaques, consider alternative diagnoses and obtain biopsy to exclude other etiologies 2
• Ulceration is not a primary feature of oral candidiasis but may develop if disease progresses to esophageal involvement 2

Treatment Options

First-Line Therapy

• Oral fluconazole is the preferred treatment as it is as effective as and superior to topical therapy in certain studies, and is more convenient and better tolerated 1
• Fluconazole is effective for initial episodes and well-tolerated 1

Alternative Systemic Therapy

• Itraconazole oral solution for 7-14 days is as effective as oral fluconazole but less well tolerated 1
• Ketoconazole and itraconazole capsules are less effective than fluconazole due to variable absorption and should be considered second-line alternatives 1

Topical Therapy

• Clotrimazole troches or nystatin suspension/pastilles can adequately treat initial episodes, though less convenient than oral fluconazole 1
• In comparative studies, nystatin achieved only 46% clinical cure compared to 86% with fluconazole in immunocompromised children 4

Special Considerations for Immunocompromised Patients

Antiretroviral Therapy (ART)

• The best prophylaxis for both oral and esophageal candidiasis is appropriate compliance to HAART (highly active antiretroviral therapy) 1
• Introduction of ART has led to a dramatic decline in prevalence of oropharyngeal candidiasis and marked diminution in refractory disease cases 1

Refractory Disease

• Fluconazole resistance is associated with cumulative exposure to fluconazole (mean value 8.7 g in patients failing therapy) 1
• In refractory cases, consider non-albicans species with intrinsic reduced azole susceptibility 1
• 93% of Candida isolates from HAART-treated patients remained susceptible to fluconazole despite repeated triazole courses 1

Clinical Pitfalls to Avoid

• Do not rely on clinical appearance alone if the patient has persistent symptoms despite antifungal treatment—obtain cultures to identify resistant species 1
• Do not confuse with oral hairy leukoplakia—thrush plaques scrape off easily, while oral hairy leukoplakia does not 1
• Do not assume vulvovaginal candidiasis indicates HIV infection—it is common in healthy women and unrelated to HIV status 1
• Do not use primary prophylaxis routinely due to drug-drug interactions with HAART, development of resistance, and availability of effective treatment 1

Progression and Complications

• Esophageal candidiasis may develop, presenting with retrosternal burning pain, altered taste, and odynophagia 1
• Endoscopic examination reveals whitish plaques that may progress to superficial ulceration of the esophageal mucosa 1
• Relapse is common and often associated with recurrence of intense pain contributing to weight loss from poor nutrition 1