Management of String Ingestion in Asymptomatic Adolescent with Pica
In this asymptomatic 16-year-old who ingested a string from a weighted blanket, obtain plain radiographs (neck, chest, abdomen) immediately to assess for the presence and location of the foreign body, and if the string is not visualized or appears to have passed beyond the esophagus without obstruction, observe clinically with instructions to return for any symptoms of obstruction, perforation, or inability to pass stool. 1
Initial Imaging Assessment
Plain neck, chest, and abdominal radiographs should be obtained first to assess for the presence, location, and configuration of the string 1. However, recognize that plain radiography has significant limitations—the false-negative rate is up to 47% for foreign bodies generally, and can reach 85% for thin objects like strings, fabric, and similar materials 1. Despite this limitation, radiographs remain the appropriate initial screening tool and may reveal signs of complications such as perforation.
Risk Stratification Based on Object Type
The string from a weighted blanket does not fall into the high-risk categories that require emergent endoscopy (within 2-6 hours), which include 1:
- Sharp-pointed objects (35% perforation risk)
- Batteries (risk of pressure necrosis and chemical burns)
- Magnets (pressure necrosis risk)
- Complete esophageal obstruction
Strings and fabric materials represent a moderate-risk foreign body that can potentially cause complications including bezoar formation, intestinal obstruction, or rarely intussusception 2, 3, but the majority (80-90%) of ingested foreign bodies pass spontaneously through the gastrointestinal tract 1.
When to Pursue Endoscopy
If the patient develops persistent esophageal symptoms (dysphagia, odynophagia, inability to swallow saliva, retrosternal pain, drooling), endoscopic evaluation should be performed even if radiographs are negative 1. For esophageal foreign bodies without complete obstruction, urgent endoscopy (within 24 hours) is recommended 1.
Since your patient is currently asymptomatic with no abdominal pain, dysphagia, vomiting, or other concerning symptoms, immediate endoscopy is not indicated.
Observation Strategy
For this asymptomatic patient, appropriate management includes:
Clinical observation with clear return precautions for development of:
- Abdominal pain or distension
- Vomiting (especially bilious vomiting)
- Inability to tolerate oral intake
- Fever
- Inability to pass stool or flatus
- Any respiratory symptoms
Monitor for passage of the foreign body in stool over the next several days
Consider CT scan if symptoms develop, as CT has superior sensitivity (90-100%) compared to plain radiography and is the key examination when complications are suspected 1
Critical Pitfall: The Underlying Pica Disorder
The most important aspect of this case is addressing the underlying pica disorder, which represents a significant risk for repeated ingestions and potentially life-threatening complications 2, 3, 4. Pica in a 16-year-old is developmentally inappropriate and warrants:
- Evaluation for iron-deficiency anemia and other nutritional deficiencies (pica is commonly associated with iron deficiency) 2
- Psychiatric/psychological evaluation to assess for comorbid conditions including depression, anxiety, autism spectrum disorder, or other developmental concerns 3, 4, 5
- Multidisciplinary behavioral intervention, as pica can lead to recurrent foreign body ingestion with complications including bezoar formation, intestinal obstruction, intussusception, and perforation 2, 3, 6
The case reports demonstrate that pica-related ingestions can progress from benign presentations to surgical emergencies, including duodenal obstruction from bezoars 2 and intussusception requiring emergency laparotomy 3.
When Surgery Becomes Necessary
Surgical intervention would be indicated if 1:
- Signs of perforation develop (fever, peritonitis, free air)
- Complete intestinal obstruction occurs
- The foreign body cannot be retrieved endoscopically and causes persistent symptoms
- Hemodynamic instability or systemic sepsis develops
The immediate risk from this single string ingestion in an asymptomatic patient is low, but the long-term risk from untreated pica is substantial and requires urgent psychiatric referral and behavioral intervention 4, 6.