Differential Diagnosis for a Child with Non-Stress Related Arm and Leg Pain

• Single most likely diagnosis:
  • Juvenile Idiopathic Arthritis (JIA): This condition is a common cause of chronic joint pain in children, affecting not just the legs but also the arms. It can present with morning stiffness, joint swelling, and pain that is not necessarily related to activity or stress.
• Other Likely diagnoses:
  • Hypermobility Syndrome: Children with hypermobile joints may experience pain due to the increased mobility and potential for joint subluxation or strain. This condition can affect both arms and legs.
  • Overuse Injuries: Although the child is not stressed and this is not attributed to growing pains, repetitive activities or overuse can lead to pain in the arms and legs, especially if the child is involved in sports or activities that involve repetitive movements.
  • Vitamin D Deficiency: Vitamin D deficiency can cause musculoskeletal pain, including pain in the arms and legs, and is a relatively common condition that can be easily tested for and treated.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Leukemia: Bone pain, including pain in the arms and legs, can be a presenting symptom of leukemia. Although rare, it is crucial to consider this diagnosis due to its severe implications and the need for prompt treatment.
  • Osteomyelitis or Septic Arthritis: Infections of the bone or joint can cause severe pain and require immediate medical attention to prevent long-term damage.
  • Neurological Conditions (e.g., Peripheral Neuropathy): Certain neurological conditions can cause pain in the arms and legs and, while less common, should not be overlooked due to their potential impact on the child's quality of life.
• Rare diagnoses:
  • Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. While rare, it can cause joint hypermobility and pain.
  • Fibromyalgia: Although more commonly diagnosed in adults, fibromyalgia can occur in children, causing widespread musculoskeletal pain, fatigue, and tender points.
  • Sickle Cell Disease: For children of appropriate ethnic backgrounds, sickle cell disease can cause episodic pain crises, including pain in the arms and legs, due to vaso-occlusive crises.