Differential Diagnosis for the 34-year-old Female Patient

The patient presents with sharp burning pain in her right groin that radiates down to the knee, a positive pregnancy test, nausea, and shortness of breath. Considering these symptoms, the differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Ectopic Pregnancy: This is the most likely diagnosis given the patient's positive pregnancy test, sharp burning pain in the groin that radiates down the thigh, and symptoms of nausea and shortness of breath. Ectopic pregnancy is a life-threatening condition where the embryo implants outside the uterus, often causing severe abdominal or pelvic pain and potentially leading to rupture and severe internal bleeding.

• Other Likely Diagnoses

  • Ovarian Cyst or Torsion: These conditions can cause severe, sudden pain and are more common in women of reproductive age. The pain can radiate down the thigh and is often accompanied by nausea and vomiting.
  • Appendicitis: Although the pain typically starts near the navel and then moves to the lower right abdomen, atypical presentations can occur, especially in pregnant women, where the appendix may be displaced due to the enlarging uterus.
  • Kidney Stone: A stone in the urinary tract can cause severe, sharp pain that radiates from the flank down to the groin, accompanied by nausea and vomiting.

• Do Not Miss Diagnoses

  • Pulmonary Embolism (PE): Given the patient's shortness of breath, PE must be considered, especially in the context of pregnancy, which increases the risk of thromboembolic events. The pain in the groin could be referred pain from a pulmonary source.
  • Ruptured Aortic Aneurysm: Although rare in young women, a ruptured abdominal aortic aneurysm can present with severe back or abdominal pain radiating to the groin and is immediately life-threatening.
  • Placental Abruption: This condition involves the placenta separating from the uterus and can cause severe abdominal pain and vaginal bleeding, although the patient denies bleeding, it's a critical condition to consider in pregnant women.

• Rare Diagnoses

  • Neurological Causes (e.g., Neuropathy, Radiculopathy): Conditions affecting the nerves can cause sharp, burning pain that radiates down the thigh but are less likely given the acute onset and the patient's other symptoms.
  • Inguinal Hernia: Although possible, especially if the patient has a history of heavy lifting or straining, the acute onset and specific radiation of pain down to the knee make this less likely compared to other diagnoses.

For nausea and pain management, medications such as ondansetron for nausea and acetaminophen or ibuprofen (if not contraindicated in pregnancy) could be considered, but the primary focus should be on diagnosing and treating the underlying cause of her symptoms.