Differential Diagnosis for the Boy with a Foot Wound

• Single most likely diagnosis
  • B. Streptococcus Pyogenes (lymphangitis): This is the most likely diagnosis given the symptoms of red streaks (indicative of lymphangitis), fever, and a swollen leg following a foot wound. Streptococcus pyogenes is a common cause of lymphangitis, which is characterized by the spread of infection along the lymphatic vessels, often presenting with red streaks and fever.
• Other Likely diagnoses
  • C. Staphylococcus Aureus: This bacterium is a common cause of skin and soft tissue infections, including those resulting from puncture wounds. While the presence of red streaks is more classically associated with streptococcal infections, Staphylococcus aureus cannot be ruled out without further testing.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • A. Clostridium Tetani: Although tetanus is less common due to vaccination, it is a critical diagnosis not to miss because of its high mortality rate if not treated promptly. The presence of a wound caused by a piece of wood (which may be contaminated with soil) increases the risk of tetanus infection.
  • D. Clostridium perfringens: This bacterium can cause gas gangrene, a severe and potentially life-threatening condition, especially in the context of a traumatic wound. Early recognition and treatment are crucial to prevent severe outcomes.
• Rare diagnoses
  • Other rare bacterial infections could potentially cause similar symptoms, but given the information provided, they are less likely and would typically be considered after the more common causes have been ruled out or in the context of specific risk factors or exposures not mentioned in the scenario.