Differential Diagnosis for Acute Onset of Vomiting

Single Most Likely Diagnosis

• Gastroenteritis: This is often the most common cause of acute vomiting, typically caused by viral or bacterial infections, leading to inflammation of the stomach and intestines. The acute onset and the presence of vomiting as a primary symptom make gastroenteritis a leading consideration.

Other Likely Diagnoses

• Food Poisoning: Similar to gastroenteritis, food poisoning can cause acute vomiting due to the consumption of contaminated food. The timing between food intake and the onset of symptoms can help differentiate it from gastroenteritis.
• Viral Gastrointestinal Infections: Infections such as norovirus can lead to severe vomiting. These are highly contagious and often seen in outbreaks.
• Medication Side Effects: Certain medications can induce vomiting as a side effect. The recent initiation of a new medication could be a clue to this diagnosis.
• Pregnancy: Morning sickness is a common symptom in early pregnancy, which can manifest as acute vomiting.

Do Not Miss Diagnoses

• Appendicitis: Although abdominal pain is the more common presenting symptom, vomiting can occur, especially if the appendix ruptures. Missing this diagnosis can lead to severe complications.
• Intestinal Obstruction: This condition can cause severe vomiting and is a surgical emergency. The vomiting may be bilious, indicating an obstruction.
• Pancreatitis: Acute pancreatitis can present with vomiting, along with severe abdominal pain. It requires prompt medical attention to manage complications.
• Diabetic Ketoacidosis (DKA): DKA can cause vomiting, and it's crucial to diagnose and treat promptly to avoid serious complications.

Rare Diagnoses

• Brain Tumors: Increased intracranial pressure from a brain tumor can cause vomiting, often accompanied by other neurological symptoms like headache or vision changes.
• Meningitis: Although more commonly associated with fever and headache, meningitis can cause vomiting, especially in children.
• Addisonian Crisis: A life-threatening condition due to adrenal insufficiency, which can present with vomiting among other symptoms like hypotension and abdominal pain.
• Porphyrias: A group of rare genetic disorders that can cause acute episodes of vomiting, abdominal pain, and neurological symptoms.