Differential Diagnosis for Diffuse Arthralgia

• Single most likely diagnosis
  • Fibromyalgia: This condition is characterized by widespread musculoskeletal pain, fatigue, and tender points, making it a common cause of diffuse arthralgia.
• Other Likely diagnoses
  • Osteoarthritis: A degenerative joint disease that can cause pain and stiffness in multiple joints, leading to diffuse arthralgia.
  • Rheumatoid Arthritis: An autoimmune disorder that causes inflammation and pain in multiple joints, often resulting in diffuse arthralgia.
  • Lupus: A chronic autoimmune disease that can cause joint pain and inflammation, among other symptoms.
  • Hypothyroidism: A condition where the thyroid gland doesn't produce enough hormones, which can cause joint pain and stiffness.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Septic Arthritis: A bacterial infection in a joint that requires prompt treatment to prevent serious complications.
  • Lyme Disease: A bacterial infection transmitted by ticks that can cause joint pain and other symptoms.
  • Rheumatic Fever: A complication of untreated strep throat that can cause joint pain and heart problems.
  • Cancer (e.g., multiple myeloma, lymphoma): Certain types of cancer can cause diffuse arthralgia, and early detection is crucial.
• Rare diagnoses
  • Relapsing Polychondritis: A rare autoimmune disorder that causes inflammation and pain in cartilaginous structures, including joints.
  • Ehlers-Danlos Syndrome: A group of genetic disorders that affect connective tissue, leading to joint hypermobility and pain.
  • Sjögren's Syndrome: An autoimmune disorder that causes inflammation and dryness in exocrine glands, including joints.
  • Mixed Connective Tissue Disease: A rare autoimmune disorder that combines features of lupus, scleroderma, and rheumatoid arthritis.