History of Present Illness (HPI)

The patient is a [insert age and sex] who presents with a 2-week history of nausea and vomiting that started around 9/5/25. The symptoms have been persistent, and the patient reports an episode on Saturday where she noticed a worm in her vomit. Her appetite has been significantly reduced, limited to chips and sips of fluids due to her inability to keep anything down. Additionally, she experiences dizziness, headache, diarrhea, and body aches. She has tried over-the-counter (OTC) pain relievers without significant relief.

Differential Diagnosis

• Single Most Likely Diagnosis
  • Gastrointestinal Infection (e.g., Giardiasis or Intestinal Parasites): The presence of a worm in the vomit, combined with symptoms of nausea, vomiting, diarrhea, and body aches, strongly suggests an infection caused by a gastrointestinal parasite. Giardiasis, caused by the Giardia lamblia parasite, is a common cause of such symptoms and could explain the patient's condition.
• Other Likely Diagnoses
  • Viral Gastroenteritis: This condition, often referred to as the stomach flu, can cause nausea, vomiting, diarrhea, and abdominal cramps. While it doesn't typically involve finding a worm in the vomit, some viral infections can lead to prolonged gastrointestinal symptoms.
  • Food Poisoning: Consuming contaminated food can lead to symptoms similar to those the patient is experiencing. However, the presence of a worm and the duration of symptoms might make this less likely.
• Do Not Miss Diagnoses
  • Appendicitis: Although less likely given the symptoms, appendicitis can sometimes present with nausea, vomiting, and abdominal pain. It's crucial to consider this diagnosis due to its potential for severe complications if not promptly treated.
  • Intestinal Obstruction: This is a serious condition that could cause vomiting, nausea, and abdominal pain. The presence of a worm might not directly relate, but any condition causing bowel obstruction needs to be ruled out due to its urgency.
• Rare Diagnoses
  • Anisakiasis: This is a parasitic infection caused by eating undercooked or raw fish containing Anisakis larvae. It can lead to gastrointestinal symptoms and, in rare cases, might involve vomiting up a worm.
  • Strongyloidiasis: A parasitic infection caused by the Strongyloides stercoralis worm, which can lead to gastrointestinal symptoms, among others. It's less common but should be considered in patients with a history of exposure to contaminated soil.