K52.21 Food protein-induced enterocolitis syndrome

Name of the Condition

• Food protein-induced enterocolitis syndrome

Summary

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy that primarily affects the gastrointestinal tract. It involves inflammation of the intestines, leading to repetitive vomiting and diarrhea, typically triggered by specific food proteins. Symptoms often occur within hours of ingestion and can range from mild to severe.

Causes

FPIES is caused by an abnormal immune response to ingested food proteins, most commonly cow’s milk, soy, or grains like rice or oats. The immune system reacts by releasing inflammatory mediators, resulting in gastrointestinal inflammation. Unlike other food allergies, FPIES does not involve IgE antibodies.

Risk Factors

• Infancy, as FPIES often presents in the first year of life.
• Family history of atopic diseases (e.g., eczema, asthma).
• Early introduction of certain foods (e.g., cow’s milk, soy) before 6 months.
• Prior episodes of FPIES or other food-related gastrointestinal reactions.

Symptoms

• Repetitive vomiting, often within 1–4 hours of food exposure.
• Profuse, watery diarrhea, sometimes with blood or mucus.
• Lethargy, pallor, or floppiness in infants.
• Dehydration or weight loss in severe cases.
• Symptoms may mimic sepsis or other acute illnesses.

Diagnosis

Diagnosis is based on clinical history, symptom timing, and exclusion of other causes (e.g., infections, metabolic disorders). Oral food challenges or elimination diets may be used to confirm triggers. Stool tests or imaging are rarely required but can rule out alternative diagnoses.

Treatment Options

• Immediate cessation of the offending food(s).
• Supportive care for dehydration (e.g., oral or IV fluids).
• Antihistamines or corticosteroids for severe reactions.
• Long-term avoidance of identified trigger foods.
• Gradual reintroduction under medical supervision for some patients.

Prognosis and Follow-Up

Most children outgrow FPIES by age 3–5, but some may retain sensitivities. Follow-up includes monitoring for new triggers and periodic food challenges. Long-term avoidance is necessary until tolerance is confirmed.

Complications

• Severe dehydration or shock from persistent vomiting/diarrhea.
• Failure to thrive if dietary restrictions are prolonged.
• Anxiety or nutritional deficiencies from overly restrictive diets.

Lifestyle & Prevention

• Maintain a food diary to track exposures and symptoms.
• Work with a dietitian to ensure balanced nutrition while avoiding triggers.
• Read labels carefully for hidden allergens (e.g., dairy in processed foods).
• Inform caregivers (e.g., schools, daycare) about the condition and emergency plan.

When to Seek Professional Help

Seek immediate care for:

• Persistent vomiting or diarrhea lasting >24 hours.
• Signs of dehydration (e.g., dry mouth, reduced urination).
• Lethargy, pale skin, or difficulty arousing.
• Suspected exposure to a known trigger.

Tips for Medical Coders

Document the specific food trigger(s) when known, as this supports coding accuracy. Include details of symptom onset, duration, and severity. Note whether the diagnosis was confirmed via elimination diet or challenge. Ensure documentation aligns with clinical findings to justify the K52.21 code.