Infections with a variety of agents can occur in any part of the gastrointestinal (GI) tract from the mouth to the anal canal. Infections can range in severity from self-limited to life-threatening, particularly if infection spreads from the gut to other parts of the body. Infections are typically caused by the ingestion of exogenous pathogens in sufficient quantities to evade host defenses and then cause disease by multiplication, toxin production, or invasion through the GI mucosa to reach the bloodstream and other tissues. In other cases, members of the normal flora of the GI tract can cause disease.
Esophagitis is an inflammatory process that can damage the esophagus.
Inflammation caused by infection, typically by fungi such as Candida or viruses such as herpes simplex virus, causes the symptoms of esophagitis. Most cases occur in immunocompromised patients, especially those with reduced cell-mediated immunity. The extent of damage to the esophagus is typically related to the severity of symptoms.
Odynophagia (pain on swallowing) and dysphagia (difficulty in swallowing) are the key clinical manifestations of esophagitis.
Candida is the most common etiology, particularly among human immunodeficiency virus (HIV)-infected patients and other immunocompromised hosts (Figure 73–1). Less common pathogens include herpesviruses such as cytomegalovirus and herpes simplex virus. Noninfectious causes also occur, such as acid reflux from the stomach and medication-induced disease (e.g., doxycycline).
Candida esophagitis. Note the many whitish lesions on the esophageal mucosa seen on endoscopy. (Reproduced with permission from McKean SC et al. Principles and Practice of Hospital Medicine. New York, NY: McGraw-Hill; 2012.)
Diagnosis may be empiric after a trial of fluconazole results in improvement for presumed Candida esophagitis. If an empiric course of fluconazole does not work, then endoscopy for visualization and biopsy could be helpful, particularly in immunocompromised hosts. Biopsy samples should be analyzed by using pathologic and microbiologic tests.
In a typical patient (e.g., HIV-infected patient) presenting with odynophagia and retrosternal pain, an empiric diagnosis of esophageal candidiasis is made and fluconazole therapy instituted. If there is no effect on symptoms and if Candida resistance is not suspected, then further diagnostics as outlined earlier may identify a specific organism that could be targeted for treatment.
One option to prevent recurrent esophageal candidiasis is by using fluconazole prophylaxis. However, this is not generally advised given the high risk of selecting for fluconazole-resistant Candida. Immune restoration in HIV-infected patients may decrease the incidence of esophageal and oropharyngeal candidiasis.