What is the diagnosis and treatment for a white plaque in the esophagus with a metallic taste?

White Plaque in Esophagus with Metallic Taste: Diagnosis and Treatment

Most Likely Diagnosis

The most likely diagnosis is esophageal candidiasis (Candida esophagitis), which presents characteristically with white plaques that cannot be washed off during endoscopy and commonly causes odynophagia, dysphagia, and altered taste sensations. 1, 2

Clinical Presentation

The white plaques in esophageal candidiasis have specific characteristics:

• White nummular lesions, cotton-like plaques, or exudates adherent to the esophageal mucosa that cannot be removed with water irrigation during endoscopy 1, 2
• In severe cases, these plaques may carpet the entire esophagus 1
• Patients typically complain of dysphagia (difficulty swallowing) or odynophagia (painful swallowing) 1, 2
• Metallic taste can occur as part of the symptom complex, though retrosternal pain, vomiting, and epigastric pain are also common 3
• Importantly, 42% of patients with candidal esophagitis may be symptom-free, so the presence of symptoms increases diagnostic certainty 3

Risk Factors to Assess

Evaluate for the following predisposing conditions (present in 88% of cases) 3:

• Immunosuppression: HIV/AIDS, malignancy, chemotherapy, radiation therapy 2
• Corticosteroid use: systemic or inhaled corticosteroids 1, 4
• Recent antibiotic use 1
• Proton pump inhibitor use 1
• Chronic conditions: diabetes mellitus, chronic kidney disease, hepatic cirrhosis, cardiac failure 1, 3
• Esophageal motility disorders: achalasia, scleroderma 2
• Chronic alcohol use 1
• Associated conditions: esophageal varices, hiatus hernia 3

Diagnostic Approach

Endoscopy with biopsy or brushings is the gold standard for diagnosis 1, 5:

• Direct visualization reveals white mucosal plaque-like lesions and exudates adherent to the mucosa 2
• Obtain esophageal brushings or biopsies to confirm yeast and pseudohyphae invading mucosal cells 2, 6
• Culture specimens to identify Candida species and antifungal sensitivities 6
• Check for concurrent oral thrush on physical examination (though only present in a minority of cases) 2, 3

Important Differential Diagnoses to Exclude

While candidiasis is most likely, consider these alternatives based on endoscopic appearance:

• Eosinophilic esophagitis (EoE): presents with white exudates, rings, furrows, and strictures, but requires ≥15 eosinophils per high-power field on biopsy 1, 7
• Herpes simplex virus (HSV) esophagitis: presents with shallow ulcers rather than plaques 1, 5
• Cytomegalovirus (CMV) esophagitis: presents with deep ulcerations 1, 5

Treatment Recommendations

Fluconazole is the preferred first-line treatment for esophageal candidiasis 1, 5:

• Dosing: 200-400 mg orally per day for 14-21 days 1
• Alternative regimen: Trimethoprim-sulfamethoxazole if fluconazole is contraindicated 1
• For immunocompetent patients, some evidence suggests candidiasis may resolve when the inciting risk factor is removed, but treatment is still recommended 1

Treatment Monitoring

• Clinical improvement should occur within days of initiating therapy 6
• If symptoms persist or recur after treatment completion, repeat endoscopy with culture is warranted to assess for fluconazole resistance or alternative diagnosis 6
• Follow-up endoscopy can confirm resolution in severe cases 4

Critical Pitfalls to Avoid

• Do not assume oral thrush must be present: only 3 of 43 patients with esophageal candidiasis had simultaneous oral candidiasis in one study 3
• Do not rely on imaging alone: biphasic esophagram can detect plaques associated with infectious esophagitis, but endoscopy with tissue sampling is required for definitive diagnosis 1
• Do not overlook inhaled corticosteroids as a risk factor: even with proper mouth rinsing technique, esophageal candidiasis can develop 4
• Recognize that immunocompetent patients can develop esophageal candidiasis, particularly with predisposing factors like PPI use, antibiotics, or esophageal dysmotility 1, 2
• Be aware of potential complications: severe cases can lead to esophageal stricture, dysphagia, weight loss, and rarely necrotizing esophagitis or fistula formation 8

When to Consider Alternative Diagnoses

If the patient has:

• Peripheral eosinophilia, atopic history (asthma, allergic rhinitis, eczema), or food impaction: strongly consider eosinophilic esophagitis and ensure adequate biopsies from multiple esophageal levels 1, 7
• Severe immunosuppression with giant ulcers: consider CMV or HIV-associated idiopathic ulcers 1, 5
• Lack of response to appropriate antifungal therapy: repeat endoscopy with comprehensive biopsies to exclude other diagnoses 6