Differential Diagnosis for Knee and Hip Pain in a 20-Month-Old with Fever and Runny Nose
- Single Most Likely Diagnosis
- Viral syndrome (e.g., transient synovitis): This is the most likely diagnosis given the combination of knee and hip pain, fever, and runny nose in a 20-month-old child. Viral syndromes are common in this age group and can cause musculoskeletal symptoms.
- Other Likely Diagnoses
- Osteomyelitis: Although less common, osteomyelitis is a possible cause of knee and hip pain in a child with fever. The presence of a runny nose might suggest a viral upper respiratory infection, but osteomyelitis should be considered, especially if the pain is severe or localized.
- Septic arthritis: This is another possible cause of joint pain in a child with fever. While the presence of a runny nose might suggest a viral etiology, septic arthritis is a serious condition that requires prompt diagnosis and treatment.
- Reactive arthritis: This condition can occur after a viral infection and cause joint pain and inflammation.
- Do Not Miss Diagnoses
- Meningococcemia: Although rare, meningococcemia is a life-threatening condition that can cause fever, joint pain, and rash. It is essential to consider this diagnosis, especially if the child appears severely ill or has a rash.
- Juvenile idiopathic arthritis (JIA): While JIA is a chronic condition, it can present acutely with fever and joint pain. Missing this diagnosis could lead to delayed treatment and long-term consequences.
- Lyme disease: If the child has been exposed to ticks, Lyme disease should be considered, as it can cause fever, joint pain, and rash.
- Rare Diagnoses
- Leukemia: Although rare, leukemia can cause bone and joint pain in children. The presence of fever and other systemic symptoms might suggest this diagnosis.
- Rheumatic fever: This condition can occur after a group A streptococcal infection and cause fever, joint pain, and cardiac symptoms.
- Sickle cell disease: If the child has sickle cell disease, vaso-occlusive crises can cause joint pain and fever.