Differential Diagnosis for a 26-year-old Pregnant Female with Severe Vomiting and Changing Mental Status

• Single most likely diagnosis:

  • Hyperemesis gravidarum: This condition is characterized by severe nausea and vomiting during pregnancy, often leading to dehydration and electrolyte imbalances. The patient's symptoms of severe vomiting for one week, inability to eat, and mild response to OTC antiemetics, along with the progression to altered mental status, could be due to severe dehydration and electrolyte disturbances associated with hyperemesis gravidarum.

• Other Likely diagnoses:

  • Urinary tract infection (UTI): UTIs are common in pregnancy and can cause systemic symptoms such as fever, chills, and altered mental status, especially if the infection progresses to pyelonephritis.
  • Dehydration and electrolyte imbalance: Severe vomiting can lead to significant dehydration and electrolyte disturbances (e.g., hyponatremia, hypokalemia), which can cause altered mental status.
  • Gestational diabetes: Although less likely to present with vomiting and altered mental status, gestational diabetes can lead to hyperglycemia, which may cause symptoms like polydipsia and could potentially lead to diabetic ketoacidosis (DKA) if not managed properly.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):

  • Preeclampsia: A condition characterized by high blood pressure and often protein in the urine, occurring after the 20th week of pregnancy. It can lead to severe complications, including eclampsia (seizures), stroke, and death if not promptly treated.
  • Diabetic ketoacidosis (DKA): Although more commonly associated with type 1 diabetes, DKA can occur in pregnancy, especially with gestational diabetes, and is a medical emergency.
  • Thromboembolic events: Pregnancy increases the risk of blood clots and pulmonary embolism, which can present with sudden onset of symptoms, including altered mental status.
  • Infection (sepsis): Any infection during pregnancy can lead to sepsis, a life-threatening condition that requires immediate medical attention.

• Rare diagnoses:

  • Wernicke's encephalopathy: A rare condition caused by thiamine deficiency, which can occur in the context of severe and prolonged vomiting, leading to neurological symptoms including altered mental status.
  • Acute fatty liver of pregnancy: A rare but serious condition that occurs in late pregnancy, characterized by liver failure, which can present with nausea, vomiting, and altered mental status.
  • Thyroid storm: A life-threatening complication of untreated or undertreated hyperthyroidism, which can present with vomiting, fever, and altered mental status.