Structural Disorders of the Esophagus

Dysphagia, a common symptom in those with esophageal disorders, can arise from a multitude of underlying causes. Dysphagia, or difficulty swallowing, refers to a sensation of impairment of the normal progression of the bolus from the mouth into the stomach. Dysphagia should be distinguished from odynophagia or pain on swallowing. Recognizing dysphagia and gauging its clinical significance appear simple. There are, however, several important points that may be brought up with the following questions:

• Is the patient truly complaining of dysphagia? In most cases, patients can clearly express symptoms of difficulty in swallowing. Alternative terms, such as food sticking or food moving down slowly into the chest can assist in identifying those with dysphagia.

• Is the dysphagia for solids, liquids, or both? Mucosal lesions, benign or malignant, that produce a narrowing of the esophageal lumen do not usually interfere with the passage of liquid substances, and dysphagia is limited to solid foods. On the other hand, disorders impairing esophageal peristalsis cause difficulty with both solids and liquids.

• Is the dysphagia intermittent or progressive? Structural lesions of the lower esophagus, such as rings and strictures, produce intermittent obstruction related to the size of the bolus, often with prolonged periods free of symptoms. In motor disorders, on the other hand, dysphagia is insidious and becomes progressively worse.

The proper clinical evaluation of dysphagia requires a detailed history.¹ Several diagnostic techniques are available; their use depends on the manifesting clinical features. The initial test, however, is often a barium swallow or an endoscopic examination. The choice between these two techniques—determining which is more useful and less costly for evaluating dysphagia—has been the subject of debate. In a patient who presents with intermittent solid dysphagia, suggesting a benign obstructing lesion such as a peptic stricture or ring, starting with endoscopy is reasonable, because it allows making the diagnosis and simultaneously treating the lesion by dilation. In cases of dysphagia to both solids and liquids and suspicion of a motor disorder, a barium swallow provides more useful information by evaluating esophageal peristalsis. The guidelines of the American Gastroenterological Association (AGA) have supported the choice of barium swallow in these cases, a recommendation with which most clinicians would agree.²

Various known causes of esophageal disorders may be classified into four different groups: disorders caused by mucosal injury, neoplastic disorders, esophageal lumen anomalies, and motor disorders.

DISORDERS CAUSED BY MUCOSAL INJURY

Definition

Mucosal injury is defined as mucosal damage resulting from an intrinsic or extrinsic agent capable of disrupting the integrity of the mucosa, leading to acute inflammation and potentially chronic inflammation, with possible permanent scarring. The most common syndromes of mucosal injuries are gastroesophageal reflux disease (GERD), infectious esophagitis, radiation esophagitis, esophagitis caused by caustic ingestion, pill esophagitis, and eosinophilic esophagitis. GERD disease is discussed in detail elsewhere in this section (“Acid Peptic Disorders”).

Prevalence

Although GERD is prevalent, causing symptoms in 20% of the population at least once a week, other causes of mucosal injury are less common.

Infectious esophagitis is rare in normal persons. In an immunocompromised patient, infection occurs today at a lesser rate than in the past because of better diagnostic and therapeutic techniques. Candida is the organism most often responsible for causing esophagitis. Radiation esophagitis is reported by some patients during treatment, but long-term lesions occur infrequently.

Caustic ingestions have been reduced dramatically since protection laws have been instituted. It is estimated that 5000 cases per year occur in the United States. The prevalence of pill-induced esophagitis is unknown. An increasing number of cases are reported, but these are few compared with the innumerable pills ingested by the public.

Eosinophilic esophagitis has gained recognition in the last few years either because of rising prevalence or increased awareness. It was originally described in children and young men, but more recent reports have involved all age groups.³

Pathophysiology

Almost all mucosal injuries are accompanied by inflammation with varying degrees of severity, including inflammation resulting from erythema, frank ulcers with potential scarring and bleeding, and strictures.

Infectious esophagitis occurs almost always in immunocompromised patients, such as post-transplantation patients or those with cancer or AIDS. Predisposing factors include diabetes, alcoholism, malnutrition, and older age, as well as treatment with corticosteroids. Diseases leading to stasis, such as achalasia, can also predispose to some infections.

Radiation esophagitis occurs with radiation therapy to the chest and mediastinum. It is dependent on the total dose administered and the duration of treatment. Injury by caustic ingestion is most commonly caused by alkali agents producing burns or by acidic agents producing necrosis.

Pill esophagitis was first reported with tetracycline. Doxycline and other tetracyclines account for most cases, but injuries have been reported with other antibiotics, antiviral agents, nonsteroidal anti-inflammatory drugs, potassium preparations, and many other medications.⁴ There is some evidence that sustained-release medications are more commonly associated with injury. The lesion occurs most often between the junction of the proximal and midesophagus at the point of impression by the aortic arch or above the esophagogastric junction.

Eosinophilic esophagitis is characterized by intense infiltration of eosinophils in the esophagus. An allergic reaction secondary to prior sensitization to food or an airborne agent is invoked as a potential pathophysiologic mechanism.

Signs and Symptoms

Mucosal injury may be asymptomatic or may be manifested by dysphagia, odynophagia, or chest pain. Patients whose nutrition may already be affected by their immunocompromised status and anorexia are further jeopardized by their inability to eat.

Candida esophagitis is often asymptomatic and is discovered at endoscopy. Pill injury is accompanied by sudden onset of severe pain over 1 to 3 days. Pain is aggravated by eating.

Eosinophilic esophagitis is manifested by dysphagia, food impaction, and chest pain. Although the condition is seen at all ages, it should be particularly suspected in young adults with dysphagia or chest pain.

Diagnosis

The diagnosis of mucosal injury is suspected based on the patient’s background and is established by a barium swallow but more precisely by endoscopy.⁵

Candida esophagitis shows typical white plaques scattered throughout the esophagus (Fig. 1). Viral infections caused by herpes simplex virus or cytomegalovirus (CMV) reveal focal or disseminated ulcers; the diagnosis is established by biopsy and special stains. About 40% of ulcers seen in patients with AIDS are not caused by a specific infection and are termed idiopathic ulcers. They are typically large and deep.

Figure 1 Candida esophagitis.

Endoscopy shows white exudates.

Radiation esophagitis is characterized by erythema and friability during the acute stages and by strictures in the late stages. Caustic ingestion is rare in the adult population and is almost always caused by suicidal attempts. Endoscopy is relatively contraindicated in the acute stages. Pill-induced esophagitis causes a typical discreet ulcer, surrounded by a normal-appearing surrounding mucosa (Fig. 2).

Figure 2 Esophageal ulcer caused by medication (pill ulcer).

The ulcer is well demarcated and has clear edges.

In eosinophilic esophagitis, endoscopy reveals multiple concentric rings or furrows (Fig. 3), but it appears normal in many cases. Barium swallow shows a narrow esophageal lumen. The diagnosis is based on the presence of 15 or more eosinophils per high-power field on esophageal biopsies.