Differential Diagnosis for Periodic Vomiting in a 22-Year-Old Female
Single Most Likely Diagnosis
- Cyclic Vomiting Syndrome (CVS): Characterized by recurrent, severe episodes of vomiting lasting hours to days, separated by periods of normal health. The absence of nausea before vomiting and the periodic nature of the episodes support this diagnosis.
Other Likely Diagnoses
- Gastroesophageal Reflux Disease (GERD): Although typically associated with nausea and heartburn, some patients may present with vomiting as a primary symptom. The periodic nature could be related to exacerbations of reflux.
- Functional Dyspepsia: A disorder of the upper gastrointestinal tract characterized by recurring symptoms of bloating, discomfort, and vomiting not explained by other pathologic conditions. The absence of food allergies or intolerances does not rule out this condition.
- Irritable Bowel Syndrome (IBS): While primarily associated with abdominal pain and changes in bowel habits, some patients with IBS may experience vomiting, especially if they have a predominant dyspeptic symptom profile.
Do Not Miss Diagnoses
- Pregnancy: Morning sickness can sometimes present atypically, with vomiting being a predominant symptom without significant nausea. Given the patient's age, pregnancy should always be considered.
- Diabetic Ketoacidosis: Although more commonly associated with diabetes, vomiting can be a presenting symptom, especially if the patient has undiagnosed or poorly managed diabetes.
- Uremic Gastritis: In patients with renal failure, uremic toxins can cause severe gastrointestinal symptoms, including vomiting.
- Porphyrias: A group of rare genetic disorders that can cause acute intermittent porphyria, characterized by episodes of severe abdominal pain, vomiting, and neurological symptoms.
Rare Diagnoses
- Rumination Syndrome: A condition where food is regurgitated into the mouth without nausea or retching, often within minutes of eating. It's more common in infants but can occur in adults.
- Eosinophilic Gastroenteritis: A rare condition characterized by eosinophilic infiltration of the gastrointestinal tract, which can cause vomiting, abdominal pain, and diarrhea.
- Gastroparesis: A condition where the stomach takes too long to empty its contents, which can cause nausea, vomiting, and feeling full after eating only a small amount of food.
Suggested Labs and Treatments
- Initial Labs: Complete Blood Count (CBC), Basic Metabolic Panel (BMP), Liver Function Tests (LFTs), Pregnancy Test, and possibly a gastrointestinal panel to rule out infections.
- Specific Tests Based on Differential:
- For CVS, consider a trial of prophylactic medications or abortive therapies during episodes.
- For GERD, a trial of proton pump inhibitors (PPIs) may be beneficial.
- For Functional Dyspepsia and IBS, treatment focuses on symptom management with medications like prokinetics, antacids, or fiber supplements.
- For Do Not Miss diagnoses, specific tests and treatments will be guided by the suspected underlying condition (e.g., blood glucose monitoring for diabetes, urine pregnancy test, etc.).
It's crucial to approach this patient with a thorough history and physical examination to guide the selection of initial labs and treatments, considering the broad differential diagnosis for periodic vomiting.