A 38-year-old man presents to the emergency department with severe pain when swallowing and progressive difficulty swallowing for the past week. He reports a 15-pound weight loss over the past 3 months and increasing fatigue. He was diagnosed with HIV infection several years ago but has not been taking antiretroviral therapy. Temperature is 37.8°C (100.0°F), blood pressure is 118/74 mm Hg, pulse is 92/min, and respiratory rate is 16/min. Physical examination reveals white plaques on the tongue and buccal mucosa that can be scraped off with a tongue depressor. Laboratory studies demonstrate a CD4+ T-cell count of 85/mm³.
Upper endoscopy reveals multiple raised white plaques throughout the esophagus.
Which of the following is the most likely cause of this patient’s symptoms?
The correct answer is:
A) Candida albicans infection
This patient has Candida esophagitis, the most common cause of infectious esophagitis in immunocompromised patients. The diagnosis is strongly suggested by HIV infection with a very low CD4 count, concomitant oral thrush, odynophagia, dysphagia, and endoscopic visualization of white adherent plaques within the esophagus.
Candida normally colonizes mucosal surfaces but can become pathogenic when cell-mediated immunity is impaired. Patients typically present with painful swallowing, difficulty swallowing, retrosternal discomfort, and oral candidiasis. Endoscopy classically demonstrates white plaque-like lesions that can often be scraped from the mucosa.
Step 2 frequently tests the differential diagnosis of infectious esophagitis in patients with advanced HIV infection:
Candida: white plaques on endoscopy
CMV: large linear ulcerations, usually in the distal esophagus
HSV: multiple small, shallow “volcano-like” ulcerations
Recognition of these characteristic endoscopic findings is a favorite board-style question. Many patients with classic oral thrush and odynophagia can be treated empirically with fluconazole without immediate endoscopy.
A useful board pearl is that esophageal candidiasis is considered an AIDS-defining illness.
Answer choice B: Cytomegalovirus infection, is incorrect.
CMV esophagitis occurs in patients with advanced immunosuppression and can cause severe odynophagia. However, endoscopy typically reveals large, linear, shallow ulcerations rather than diffuse white plaques. CMV is often diagnosed with biopsy demonstrating viral inclusion bodies.
Answer choice C: Eosinophilic inflammation, is incorrect.
Eosinophilic esophagitis usually presents with chronic dysphagia and food impaction, particularly in patients with atopic disease. It is not associated with oral thrush, advanced HIV infection, or diffuse white esophageal plaques.
Answer choice D: Gastroesophageal reflux disease, is incorrect.
GERD commonly causes heartburn and regurgitation. Although erosive esophagitis can occur, GERD does not produce oral candidiasis or characteristic white plaque lesions.
Answer choice E: Herpes simplex virus infection, is incorrect.
HSV esophagitis can cause odynophagia in immunocompromised patients. However, endoscopy classically demonstrates multiple small, well-circumscribed ulcerations rather than white plaques. Patients may also have concurrent oral or labial herpetic lesions.
Key Learning Point
Candida esophagitis is the most common infectious esophagitis in patients with advanced HIV infection and presents with odynophagia, dysphagia, oral thrush, and white plaque-like lesions on endoscopy. Distinguishing Candida, CMV, and HSV esophagitis based on endoscopic appearance is a high-yield Step 2 concept.
