Diseases similar to arthritis (RA)

Osteoarthritis

• Normal blood samples

Borrelia arthritis

• Often knee-jointed, non-symmetric, CCP antibody. Borrelia tests knock out

Fibromyalgia

• Widespread pain, no obvious swelling, normal blood tests

Haemochromatosis

• Fewer attacked joints, high hemoglobin (blood percentage) and very high iron level (ferritin)

Lupus (Systemic lupus erythematosus, SLE)

• Not a-CCP, but ANA is clearly elevated, rash

Mixed connective tissue disease (MCTD)

• No CCP antibody, but ANA and RNP antibody

Multicentric Reticulohistiocytosis

• Rare disease
• Nodes under the skin (histiocytes / macrophages)
• Arthritis in PIP and DIP joints

Neuropathy 

• Disease of the nervous system, numbness, pain or decreased feeling, most often in the feet. Normal blood samples (check B12 vitamins in blood sample). May occur in other rheumatic diseases, especially Vasculitis

Pachydermodactyly

• Swollen joint fibromatosis, typically middle finger (PIP) in the fingers

Polymyalgia rheumatica

• Higher age
• Quick start
• Rare joint swelling
• Not CCP antibody

Psoriatic arthritis

• Not CCP Antibodies in blood

Sarcoidosis (with swollen joints)

• Typical lung abnormailities, not α-CCP

Septic arthritis

• Infection
• Mycobacterium marinum infection
• Granulomatous skin symptoms, arthritis, fever

Metabolism, low (hypothyroidism)

• Normal blood samples excluding metabolic tests (f-T4 is low, TSH is high)

Gout

• Not CCP Antibodies in blood
• High uric acid
• Uric acid crystals in joint fluid

Virus Infections

• Parvo virus (reference: Moor TL, 2000)
• HIV (Reference: Cunha BM, 2015)

Back to Rheumatoid arthritis

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