Oral Candidiasis (Pseudomembranous Type / Thrush)

What the Image Shows

Clinical Correlation

• Non-diabetic (rules out the most common predisposing factor)
• Burning with spicy food — hallmark symptom of oral candidiasis, especially the erythematous/atrophic subtype which accompanies the pseudomembranous form
• Normal B12 and D3 — rules out glossitis from nutritional deficiency

Differential Diagnosis to Consider

Predisposing Factors to Investigate (Non-Diabetic)

• Recent antibiotic use (most common non-diabetic cause)
• Inhaled corticosteroid use (e.g., asthma)
• Dry mouth / salivary hypofunction (Sjögren's, anticholinergic drugs)
• Denture wearing (even partial)
• Smoking
• HIV / immunosuppression — Goldman-Cecil notes: "If the patient does not use dentures and has not taken antibiotics recently, underlying immunosuppression should be considered"
• Malnutrition, malignancy, immunosuppressive therapy

Management

First-Line Treatment

• Clotrimazole troches 10 mg, dissolve slowly in mouth 5× daily for 7–14 days (first-line topical)
• Nystatin suspension 400,000–600,000 units, swish and swallow, 4× daily for 7–14 days
• Nystatin pastilles — alternative topical form

• Fluconazole — 200 mg loading dose on Day 1, then 100 mg daily × 14 days (drug of choice per Goldman-Cecil)
• Systemic antifungals may be less effective in patients with severe salivary hypofunction (insufficient saliva to distribute drug)

Supportive Measures

• Avoid spicy, acidic, and hot foods until resolved
• Maintain good oral hygiene — gentle brushing of the tongue
• If wearing dentures: soak dentures in antifungal solution (nystatin or dilute chlorhexidine) overnight
• Avoid mouthwashes with alcohol (worsens dryness/burning)
• Stay well hydrated — stimulates saliva flow

Recurrence Prevention

• Address underlying cause (stop antibiotics if possible, switch inhaler technique, rinse mouth after inhaled steroids)
• Treat recurrences with fluconazole; investigate for HIV/immunosuppression if recurrent without clear cause

When to Escalate

• No response to 2 weeks of fluconazole → consider fluconazole-resistant Candida → switch to itraconazole, posaconazole, or voriconazole
• Odynophagia or dysphagia → suspect esophageal candidiasis → requires systemic treatment and endoscopy
• No obvious predisposing factor → HIV testing and immunological workup

⚠️ Clinical note: This is a visual and contextual assessment, not a definitive diagnosis. Confirmation can be done by scraping — if the white material lifts off revealing an erythematous base, this supports candidiasis. KOH preparation of the scraping showing hyphae/pseudohyphae confirms it.

Voriconazole Dosing

For Oral Candidiasis (Fluconazole-Resistant)

Key Pharmacology Points (Goodman & Gilman)

• Therapeutic drug monitoring: Target serum trough 1–5 mg/L to maximise efficacy and minimise toxicity
• Metabolised by CYP2C19 > CYP2C9 > CYP3A4 — also inhibits these enzymes (significant drug interactions)
• QTc prolongation — check baseline ECG
• Transient visual disturbances / hallucinations common after the first dose (photopsia, colour changes)
• Contraindicated in pregnancy

Context for This Patient

1. Clotrimazole troches / Nystatin suspension (topical)
2. Fluconazole 200 mg load → 100 mg/day × 14 days (systemic first-line)
3. Voriconazole 200 mg oral q12h (for fluconazole-resistant cases)
4. Echinocandins (caspofungin, micafungin) for refractory/invasive disease