Most common: Viral arthritis, Osteoarthritis
Osteoarthritis
Viral arthritis (see common types of viruses)
Rheumatoid arthritis
Inflammatory osteoarthritis
Psoriatic arthritis
Inflammatory bowel disease
Polyarticular gout
Pseudogout
Bacterial endocarditis
Lyme disease
Disseminated gonococcal infection
Septic joint
Other infections
Reactive arthritis
Rheumatic fever
Enteric infection e.g. Whipple’s disease
Ankylosing spondylitis
Systemic lupus erythematosus
Systemic vasculitis
Systemic sclerosis
Polymyositis/dermatomyositis
Polymyalgia rheumatica
Scleroderma
Still’s disease
Behçet’s syndrome
Relapsing polychondritis
Autoinflammatory disorders
Sarcoidosis
Wegener’s granulomatosis
Amyloidosis
Palindromic rheumatism
Familial Mediterranean fever
Malignancy
Hyperlipoproteinemias
Polyarteritis nodosa
Neuropathic pain; radiculopathy, neuropathy
Acute myelopathy
Metabolic bone disease
Ehlers Danlos (Hypermobility syndrome)
Depression
Multiple sites of bursitis or tendinitis
Soft tissue abnormalities
Sickle cell disease
Hypothyroidism
Adrenal insufficiency
Drug-induced lupus
Thinking about the differential diagnosis
Inflammatory vs. Noninflammatory polyarthritis
It helps to classify the pain as noninflammatory or inflammatory in origin. “Noninflammatory arthritis, which is mostly related to osteoarthritis, does not have inflammatory features, such as warm or swollen joints. Osteoarthritis usually presents with less than one hour of morning stiffness and pain that is aggravated by activity and improves with rest. A review of systems is usually negative for rashes, oral ulcers, or other internal organ involvement. In contrast, inflammatory arthritis generally causes warm, swollen joints; prolonged morning stiffness; and positive findings on a review of systems.” AAFP 2015
Further Reading
Robert H Shmerling, MD. Evaluation of the adult with polyarticular pain. Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc. http://www.uptodate.com (Accessed on December 24, 2017)
Am Fam Physician. 2015 Jul 1;92(1):35-41. Differential Diagnosis of Polyarticular Arthritis. https://www.aafp.org/afp/2015/0701/p35.html
https://www.ncbi.nlm.nih.gov/pubmed/6287963