Differential Diagnosis for the 11-month-old Girl
The patient's presentation of intermittent episodes of crying and hip flexion, along with increased tiredness and poor appetite, suggests a range of possible diagnoses. The following categories organize these potential diagnoses based on their likelihood and the urgency of their consideration:
Single Most Likely Diagnosis
- Intussusception: This condition, where a part of the intestine slides into an adjacent part, is a common cause of intermittent abdominal pain in infants, often accompanied by episodes of crying and drawing up of the legs. The patient's age, symptoms of abdominal tenderness, and episodes of pain are consistent with this diagnosis.
Other Likely Diagnoses
- Viral gastroenteritis: The patient's poor appetite, mild abdominal tenderness, and slightly dry oral mucous membranes could suggest a viral infection affecting the gastrointestinal tract.
- Urinary tract infection (UTI): Although less common in infants without urinary symptoms, a UTI could cause abdominal discomfort and irritability.
- Constipation: Could cause abdominal pain and discomfort, though typically not intermittent episodes of severe pain.
Do Not Miss Diagnoses
- Appendicitis: Although rare in infants, appendicitis is a surgical emergency that can present with abdominal pain and vomiting. The mild abdominal tenderness without guarding or rebound tenderness does not rule out early appendicitis.
- Testicular torsion (in boys) or ovarian torsion (in girls): These are emergencies that can cause severe, intermittent pain. While the patient is a girl, and ovarian torsion is less common than testicular torsion, it remains a critical diagnosis not to miss.
- Sepsis or meningitis: These life-threatening conditions can present with nonspecific symptoms such as irritability, poor feeding, and lethargy in infants. The patient's increased tiredness and poor appetite warrant consideration of these diagnoses.
Rare Diagnoses
- Lead poisoning: Could cause abdominal pain and constipation, among other symptoms, but is less likely without a known exposure history.
- Neurologic conditions (e.g., infantile spasms, migraines): These could potentially cause episodic crying and changes in behavior, though they are less common and would typically have other distinguishing features.
- Metabolic disorders: Certain metabolic conditions can cause episodes of illness with nonspecific symptoms, including abdominal pain and lethargy, but these are rare and often have other specific findings or a family history.