What is the differential diagnosis of joint pain in childhood?
There are at least 110 illnesses associated with arthritis or related musculoskeletal syndromes in childhood. The broad differential diagnosis can be remembered with the mnemonic PRIME BONE PAIN:
- P —Pharmacologic: serum sickness; drug-induced lupus.
- R —Rheumatologic: JIA; systemic lupus erythematosus; Sjogren syndrome; systemic sclerosis/mixed connective tissue disease; vasculitis; dermatomyositis; sarcoidosis.
- I —Infectious/postinfectious: bacterial (osteomyelitis, discitis, septic arthritis, rheumatic fever, reactive arthritis, Lyme disease); viral (“toxic/transient” synovitis, human immunodeficiency virus, hepatitis B or C, parvovirus, Epstein–Barr virus, Herpes, rubella vaccination).
- M —Metabolic/genetic: mucopolysaccharidoses; mucolipidoses; heritable collagen disorders (Marfan, etc.); pseudorheumatoid chondrodysplasia.
- E —Episodic: autoinflammatory syndromes (FMF, HIDS, TRAPS, CAPS, BLAU, PAPA, DIRA). See Chapter 79 : Periodic Fever and Familial Autoinflammatory Syndromes.
- B —Blood/hematologic: sickle cell anemia; hemophilia.
- O —Orthopedic: chondromalacia patellae; Osgood–Schlatter disease (apophysitis of the tibial tubercle); osteochondritis dissecans; Legg–Calvé–Perthes disease; slipped capital femoral epiphysis.
- N —Neoplastic: neuroblastoma; leukemia/lymphoma; bone tumors (osteoid osteoma, osteochondroma, osteosarcoma, Ewing sarcoma); pigmented villonodular synovitis; metastases.
- E —Endocrine: hypercortisolism; hypothyroidism; rickets; diabetes mellitus.
- P —Pain amplification syndromes/psychosomatic: complex regional pain syndrome (CRPS); fibromyalgia; conversion reactions.
- A —Accidental/trauma.
- I —Inflammatory: inflammatory bowel disease.
- N —“Normal variants”: “growing pains”; benign hypermobility.
