AIDS: Esophageal conditions due to fungal, ulcerative, and neoplastic causes often signal the onset of symptomatic HIV infection. Most cases are fungal and due to Candida albicans, which is characterized by esophageal inflammation causing pain on swallowing (dysphagia and odynophagia). Ulcerative esophageal disease is commonly associated with cytomegalovirus (CMV), idiopathic causes, and herpes simplex virus (HSV). CMV, characterized by odynophagia resulting from ulcerations in the distal third of the esophagus, is clinically indistinguishable from idiopathic ulceration. HSV is more widespread and abrupt than other ulcerative processes, and its erosive injury can cause painful swallowing, ulceration and oral cavity lesions. Patients with esophageal distress, low CD4 counts, and little possibility of other GI conditions most likely suffer from Candida infection and should immediately begin an empiric trial of antifungal therapy. If an individual's first bout of odynophagia does not respond to empiric oral azole therapy, the diagnosis of fungal esophagitis is probably incorrect and an upper endoscopic evaluation should be performed. Patients generally respond quickly and completely to treatment of a first episode of fungal esophagitis; therefore, neither primary prophylaxis nor long-term suppressive therapy are recommended due to the risk of infection with a resistant strain. Failure of patients on suppressive therapy to respond to antifungal medication usually indicates resistant fungal infection that may require treatment with intravenous amphotericin. If CMV-isolated esophagitis is diagnosed, the patient should begin intravenous ganciclovir, followed by IV foscarnet if the healing after three weeks is minimal.