Differential Diagnosis for a Child with Fever and Vomiting

Single Most Likely Diagnosis

• Viral Gastroenteritis: This is the most common cause of fever and vomiting in children, often due to rotavirus, norovirus, or adenovirus. The symptoms typically include diarrhea, which may not always be present at the time of presentation.

Other Likely Diagnoses

• Food Poisoning: Bacterial or viral infections from contaminated food can cause fever, vomiting, and sometimes diarrhea.
• Urinary Tract Infection (UTI): Especially in younger children, UTIs can present with nonspecific symptoms such as fever and vomiting.
• Respiratory Infections: Pneumonia or other respiratory infections can cause fever and vomiting, especially if the child is not able to keep fluids down.
• Appendicitis: Although less common, appendicitis should be considered, especially if the child complains of abdominal pain.

Do Not Miss Diagnoses

• Meningitis: A bacterial or viral infection that inflames the meninges, which can present with fever, vomiting, headache, and stiff neck. It's critical to diagnose early due to the high risk of complications and death.
• Septicemia: Bacterial infection in the blood, which can cause fever, vomiting, and other systemic symptoms. Early recognition and treatment are crucial.
• Intussusception: A condition where a part of the intestine slides into an adjacent part, which can cause intestinal obstruction. It's a medical emergency that requires prompt diagnosis and treatment.
• Diabetic Ketoacidosis (DKA): Especially in children with diabetes, DKA can present with vomiting, fever, and abdominal pain.

Rare Diagnoses

• Reye's Syndrome: A rare but serious condition that causes swelling in the liver and brain, often associated with aspirin use during a viral infection.
• Adrenal Insufficiency: A condition where the adrenal glands do not produce enough hormones, which can cause vomiting, fever, and other systemic symptoms.
• Inborn Errors of Metabolism: Certain genetic disorders that affect the body's metabolism can cause episodes of fever, vomiting, and other symptoms.

Steps to Take and Medicines to Give

1. Assess hydration status and provide oral rehydration therapy or intravenous fluids as needed.
2. Monitor vital signs closely.
3. Perform a physical examination to look for signs of infection or other causes of symptoms.
4. Order diagnostic tests as indicated by the history and physical examination, such as complete blood count (CBC), blood culture, urine analysis, and imaging studies.
5. Administer antipyretics like acetaminophen or ibuprofen for fever, but avoid aspirin in children due to the risk of Reye's syndrome.
6. Consider antibiotics if a bacterial infection is suspected, but only after appropriate cultures have been obtained.
7. Provide antiemetics for vomiting, but use them judiciously to avoid masking symptoms of more serious conditions.

It's crucial to approach each child individually, considering their specific symptoms, medical history, and physical examination findings to guide the diagnostic process and treatment plan.