Differential Diagnosis for a 30-year-old 5th month pregnant lady

Single most likely diagnosis

• Viral Gastroenteritis: The patient's symptoms of diarrhea, vomiting, fever, and dizziness, along with a recent history of hypotension, are consistent with viral gastroenteritis, which can lead to dehydration and electrolyte imbalances. The low WBC count (3.2) might be seen in viral infections.

Other Likely diagnoses

• Food Poisoning: Similar to viral gastroenteritis, food poisoning can cause sudden onset of diarrhea, vomiting, fever, and dizziness. The recent episode of hypotension could be due to severe dehydration.
• Urinary Tract Infection (UTI): UTIs are common in pregnancy and can cause systemic symptoms such as fever and dizziness. However, the presence of diarrhea and vomiting is less typical for UTI.
• Pregnancy-related Hypotension: Pregnancy can cause changes in blood pressure regulation, and some women may experience hypotension, especially when changing positions. However, the combination with other symptoms suggests an underlying cause like dehydration.

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

• Septic Shock: Although the patient's blood pressure has normalized, the history of significant hypotension (60/40 mmHg) and current symptoms could be indicative of an early stage of septic shock, especially with a potential source of infection (e.g., UTI, pneumonia). The low WBC count could be a sign of severe infection.
• Pulmonary Embolism: Pregnancy increases the risk of pulmonary embolism, and symptoms like shortness of breath (Sob) and dizziness could be indicative of this condition. It's crucial to consider PE in any pregnant patient with unexplained respiratory symptoms.
• Eclampsia: Although less likely given the absence of seizures and the patient being only in her 5th month, eclampsia can present with systemic symptoms including fever, vomiting, and hypotension. It's a condition that requires immediate attention.

Rare diagnoses

• Addisonian Crisis: This is a rare condition where the adrenal glands do not produce enough cortisol and aldosterone, leading to hypotension, dehydration, and potentially life-threatening complications. The recent episode of severe hypotension could suggest this, but it would be uncommon.
• Hyperemesis Gravidarum: Although typically presenting earlier in pregnancy, hyperemesis gravidarum can cause severe vomiting leading to dehydration and electrolyte imbalances. However, the presence of fever and diarrhea is not typical for this condition.