Differential Diagnosis
- Single most likely diagnosis
- Acetaminophen: The patient's presentation with lethargy, vomiting, mild icterus, hepatomegaly, and markedly elevated transaminase levels is highly suggestive of acetaminophen toxicity, which is a common cause of acute liver failure. The history of taking an effervescent over-the-counter medicine for an upset stomach, which likely contained acetaminophen, further supports this diagnosis.
- Other Likely diagnoses
- Aspirin: Although less likely than acetaminophen, aspirin toxicity can also cause vomiting, lethargy, and elevated liver enzymes. However, the clinical presentation and laboratory results are more consistent with acetaminophen toxicity.
- Ibuprofen: Ibuprofen overdose can cause gastrointestinal symptoms, such as vomiting, but it is less likely to cause severe liver injury compared to acetaminophen.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Reye's syndrome: This rare but potentially fatal condition is associated with the use of aspirin during viral infections, such as influenza or varicella. Although the patient's symptoms are more consistent with acetaminophen toxicity, Reye's syndrome should be considered in the differential diagnosis due to its high mortality rate.
- Salicylate toxicity: Although less likely, salicylate toxicity can cause severe symptoms, including lethargy, vomiting, and liver injury. It is essential to consider this diagnosis, especially if the patient has been taking aspirin or other salicylate-containing products.
- Rare diagnoses
- Guaifenesin toxicity: Guaifenesin is an expectorant commonly found in over-the-counter cough medicines. While it is unlikely to cause severe liver injury, it can cause gastrointestinal symptoms, such as vomiting, in rare cases.
- Loperamide toxicity: Loperamide is an anti-diarrheal medication that can cause gastrointestinal symptoms, such as vomiting, but it is unlikely to cause severe liver injury.