Differential Diagnosis for 19-year-old Boy with Gastrointestinal Symptoms and Rash
Single Most Likely Diagnosis
- Food Poisoning: This is the most likely diagnosis given the onset of symptoms after eating local street food. The symptoms of vomiting, diarrhea, and fatigue are consistent with food poisoning, which can be caused by a variety of pathogens such as bacteria (e.g., Salmonella, E. coli), viruses (e.g., Norovirus), or parasites.
Other Likely Diagnoses
- Viral Gastroenteritis: Similar to food poisoning, viral gastroenteritis can cause severe vomiting and diarrhea, leading to dehydration and fatigue. The recent consumption of street food increases the risk of viral infections.
- Bacterial Gastroenteritis: Bacteria like Campylobacter, Salmonella, or Shigella can cause severe gastrointestinal symptoms, including diarrhea and vomiting, after consuming contaminated food.
- Dehydration: Given the symptoms of reduced urination and fatigue, dehydration is a likely complication of the gastrointestinal symptoms, regardless of the underlying cause.
Do Not Miss Diagnoses
- Hemolytic Uremic Syndrome (HUS): Although less common, HUS is a potentially life-threatening condition that can occur after certain bacterial infections (e.g., E. coli O157:H7). It is characterized by hemolytic anemia, acute kidney injury, and thrombocytopenia. The "red spots" (petechiae or purpura) could be indicative of a bleeding disorder or thrombocytopenia.
- Septicemia: Bacterial sepsis can occur if the gastrointestinal infection spreads to the bloodstream, leading to a systemic inflammatory response syndrome (SIRS), which can be life-threatening if not promptly treated.
- Toxic Shock Syndrome: This is a rare but potentially fatal condition caused by bacterial toxins, often associated with Staphylococcus aureus or Streptococcus pyogenes. Symptoms can include fever, rash, skin peeling, and multi-organ failure.
Rare Diagnoses
- Leptospirosis: A zoonotic infection that can cause a wide range of symptoms, including gastrointestinal symptoms, fever, and rash. It is less common but should be considered in individuals who have been exposed to contaminated water or soil.
- Rickettsial Infections: Such as Rocky Mountain spotted fever, which can cause fever, headache, and a characteristic rash. These infections are transmitted by ticks and are less likely given the context of eating street food, but could be considered if the patient has been in areas where ticks are prevalent.