Differential Diagnosis
The patient presents with nausea, vomiting, and abdominal pain, which are non-specific symptoms that can be associated with various conditions. Based on the provided information, the following differential diagnoses are considered:
- Single most likely diagnosis
- Gastroenteritis: The patient's symptoms of nausea, vomiting, and abdominal pain, along with fever, chills, myalgias, and malaise, are consistent with gastroenteritis. The absence of diarrhea and the presence of pain in the left lower quadrant that increases with breathing and abdominal muscle movement may suggest a more complex condition, but gastroenteritis remains a plausible explanation.
- Other Likely diagnoses
- Peptic ulcer disease: The patient's pain is described as worse after eating and "hurting like indigestion," which is consistent with peptic ulcer disease. The use of famotidine (Pepcid) by the family doctor also suggests that peptic ulcer disease was considered.
- Viral hepatitis: Although the patient's transaminase levels are only slightly elevated (40 U/L), viral hepatitis cannot be ruled out entirely, especially given the initial diagnosis by the family doctor.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Appendicitis: Although the patient's pain is not typically localized to the right lower quadrant, appendicitis can present with atypical symptoms, especially in young adults. The presence of pain in the left lower quadrant that increases with breathing and abdominal muscle movement raises concern for a possible ruptured appendix or other serious condition.
- Pneumonia: The patient's respiratory rate is elevated (28 per minute), and the presence of fever, chills, and myalgias could suggest a pulmonary infection. Although the physical examination of the lungs is unremarkable, pneumonia should be considered, especially given the potential for atypical presentation.
- Rare diagnoses
- Pancreatitis: Although the patient's symptoms are not typical for pancreatitis, the presence of abdominal pain and elevated white blood cell count raises concern for a possible pancreatic infection or inflammation.
- Inflammatory bowel disease: The patient's symptoms of abdominal pain, nausea, and vomiting could be consistent with inflammatory bowel disease, although the absence of diarrhea and other typical symptoms makes this diagnosis less likely.
Additional history information that would be helpful to obtain includes:
- A more detailed description of the patient's pain, including its severity, duration, and any factors that exacerbate or relieve it
- Information about the patient's dietary habits and any potential foodborne illnesses
- A review of the patient's medication list, including any over-the-counter or prescription medications that may be contributing to the symptoms
- A social history, including any travel or exposure to sick contacts
Additional laboratory or testing that would be helpful to obtain includes:
- Complete metabolic panel to evaluate liver and kidney function
- Lipase or amylase levels to evaluate for pancreatitis
- Blood cultures to evaluate for bacteremia or sepsis
- Imaging studies, such as a chest X-ray or abdominal CT scan, to evaluate for pneumonia or other abdominal pathology.