Children commonly swallow foreign bodies. Coins are the most commonly swallowed foreign body that comes to medical attention in the U.S.; in other countries, those related to food, such as fish bones, are most common.  Preschoolers of both sexes, adolescent boys, and children with mental health issues are at the highest risk. Even infants may swallow foreign bodies that are given to them, perhaps by older siblings.  Most swallowed foreign bodies will harmlessly pass through the GI tract, but some will lead to health problems if they become lodged (e.g., too large to pass or small objects like a pill that may adhere to a moist surface); traumatize the mucosa (e.g., sharp or pointed object, like a razor blade or pin), or cause caustic burn injury (e.g., biologically active substances, such as a button battery or a medication patch).

Etiology

Typically, pediatric foreign body ingestion is accidental, although deliberate ingestion can also occur. Most cases occur in children due to the ingestion of small objects. Children with psychological impairment are also at high risk for ingesting foreign bodies.

Button/disc batteries may cause serious injury if lodged in the esophagus, nose, ear, or another orifice for even a brief period.  The highest risk is associated with larger lithium-based batteries, but all models carry some risk. Children with suspected button/disc battery ingestion should be managed urgently; a battery lodged in the esophagus should be removed without delay. Treatment algorithms for button/disc battery ingestions are widely available.  A button/disc battery may be distinguished from a coin when seen on a radiograph by its characteristic two-layer appearance when seen on-end, or a circle-within-a-circle appearance when seen front-to-back. 

Small, powerful magnets, such as those found in some toys and games, may cause serious injury to the intestines, as the strong attraction between two or more magnets may cause them to erode through intervening tissues. A single swallowed magnet in combination with another metallic object, most notably a button/disc battery, may also cause injury.

Preexisting GI tract abnormalities, such as previous surgery, strictures, fistulas, diverticula, or functional abnormalities, increases the risk of a swallowed foreign body becoming lodged at the site of the abnormality.

Epidemiology

The vast majority of ingestions occur in the six months to three year age range.  Children and mentally ill patients commonly swallow foreign bodies.  Coins are most commonly swallowed in the U.S. while in other countries, fish bones tend to be the most common form of ingestion. Occasional death reports from ingestion occur, but mortality is generally very low from foreign body ingestion.

Over the last two decades, magnet ingestion has increased in the US, especially in children less than five years old.

Pathophysiology

The most common complication of foreign body ingestion in children is obstruction of the object in the esophagus, although the foreign body may become lodged anywhere in the gastrointestinal (GI) tract. Once lodged, the object may partially or completely obstruct the GI tract. Furthermore, some foreign bodies may erode through the GI tract, causing complications due to perforation or migration of the object.  Certain patients may be at higher risk for retention, obstruction, or perforation. These include younger patients with smaller anatomy, those with prior upper GI tract surgery, history of significant gastroesophageal reflux or eosinophilic esophagitis, neuromuscular disease states, or presence of congenital malformations.

Foreign bodies are likely to get lodged in children with preexisting esophageal abnormalities. Once a foreign body reaches the stomach, it is less likely to be associated with complications. However, some foreign bodies can become trapped at the ileocecal valve.

History and Physical

In cases of suspected foreign body ingestion, the airway (including the oropharynx) and breathing should be evaluated promptly.  A foreign body that has become obstructed within or injured the esophagus may cause chest pain or a foreign body sensation. Symptoms may be more notable when swallowing. Younger children may drool, gag, vomit, or refuse food. Hematemesis and cough may be present.  A foreign body lodged in the stomach or intestines may cause abdominal pain, vomiting, or bloody stools.  If present for a prolonged period, fever or weight loss may develop. A foreign body that has completely obstructed the esophagus will cause more dramatic symptoms.

Importantly, however, there may be no signs or symptoms (or they may be subtle and hard to recognize) in pediatric ingestions. Since many foreign body ingestions by children are unwitnessed, the possibility of non-specific symptoms being caused by foreign body ingestion should always be considered.  In one series, for example, only half of the patients had any symptoms whatsoever despite witnessed ingestion of a foreign body.

Swallowed foreign bodies that contain nickel may cause systemic signs and symptoms, such as rash or pruritus, in patients with nickel sensitivity.

Evaluation

If a complete history and physical examination (including examination of the pharynx) suggest possible foreign body ingestion, the provider must decide whether imaging is indicated.  If so, usually plain radiographs suffice initially. Healthy children with recent, low-risk ingestions may be simply observed.  Metallic swallowed foreign bodies, such as coins and batteries, will show up readily on a plain radiograph. Metal detectors are occasionally used, especially in the setting of known coin ingestion. It is not unusual to find an unexpected foreign body on a radiograph obtained for the evaluation of non-specific symptoms, such as a cough, fever, or weight loss.  Most glass fragments are visible on a radiograph. Radiolucent objects, such as a large piece of meat or a plastic toy, may not be apparent on radiographs, although their edges or irregularities may still be noticeable on radiography. Affected patients may require more advanced imaging techniques, such as contrast-enhanced radiography or MRI scanning, but these patients may also be considered for treatment (e.g., endoscopy) without further imaging.

Treatment / Management

Most children who have swallowed a foreign body do not require invasive treatment. Asymptomatic, previously healthy children who have swallowed low-risk foreign bodies typically will do well. Patients and caregivers should be instructed on the signs and symptoms of subsequent potential complications.

Foreign bodies that are lodged in the esophagus are most commonly removed endoscopically. Some, especially those lodged in the lower esophagus at the gastroesophageal junction, will pass spontaneously into the stomach after a few hours; this is safe for coins and similar small, inert objects, in children with otherwise normal GI tracts who are at low risk of further complication as the object passes through the remainder of the GI tract. Some centers will remove small esophageal foreign bodies, especially coins, with a bougie or a balloon catheter; these require substantial experience. Endoscopy is also typically used to remove large, sharp, pointed, or other high-risk objects from the stomach, or in patients for whom continued passage of the object through the GI tract poses a risk. Objects in the lower GI tract should be managed in conjunction with a specialist, who may recommend surgical removal.

Differential Diagnosis

The differential for pediatric foreign body ingestion is broad, but the following entities should be considered (or ruled out) in patients presenting with such complaints:

• Esophagitis
• Pyloric stenosis
• Laryngitis
• Pharyngitis
• Globus sensation
• Esophageal rupture

Prognosis

The outcomes and prognosis in pediatric foreign body ingestion are generally good, with most patients tolerating passage of ingested objects without intervention.  Even in scenarios where intervention is needed, mortality and morbidity are low.  High-risk ingestions (button batteries, magnets) can be associated with complications, and in rare instances, death.

Systemic reactions associated with zinc allergy have been reported. Esophageal foreign bodies have been known to cause mediastinitis, perforation, and pneumomediastinum. Button batteries cause the highest morbidity, and thus, they need to be removed as soon as the diagnosis is made. Finally, procedures to remove foreign bodies can also cause complications- either from the anesthesia or the procedure. 

Complications

As stated above, esophageal obstruction is the most common complication of foreign body ingestion in children.  However, some foreign bodies may erode through the GI tract, causing complications due to perforation or migration of the object.    The following complications may be observed in rare cases:

• Esophageal or stomach perforation
• Pneumothorax
• Mucosal erosion
• Aortoenteric fistula
• Pressure necrosis
• Failure to thrive secondary to decreased oral intake