Pain in Just One Joint — First, rule out an Emergency:
New onset of acute, single red, hot, swollen joint could be Septic Arthritis
- Bacteria in joint (usually Staph) — very destructive; can spread to blood (& be lethal)
- Almost always with fever (except the very elderly)
Conditions that may look like septic arthritis, but aren’t: Bursitis, Cellulitis, Hemarthrosis (blood in joint).ย To rule-out Septic Arthritis:
- If examiner can wiggle a relaxed joint in one or another direction without pain, unlikely to be true arthritis (joint disease). May be bursitis — see topic Musculoskeletal Pain.
- If same as above, but especially if pain with lightly scratching red, hot skin, or stretching skin without moving joint, likely Cellulitis (bacterial skin infection)
- Hemarthrosis occurs with trauma, also if bleeding disorder like Hemophilia
The vast majority of patients with Septic Arthritis have a risk factor:
* Age >80 * Rheumatoid Arthritis * Known chronic joint disease gg | * Skin Infection * Diabetes * Prosthetic (artificial) Joint gg | * Recent joint surgery * Recent steroid injection * Injection Drug Use * Alcoholism |
Diagnosis of Septic Arthritis: aspirate fluid from joint, in ER
- If high white cell count (suggests bacteria), IV antibiotics pending results of culture
- Joint aspiration diagnoses Hemarthrosis if fluid very bloody
If no suggestion of Septic Arthritis, continue on below
Pain in just One, or a Few, Joints
(Monoarticular / Oligoarticular Arthritis
Causes of Monoarticular *** / Oligoarticular Arthritis
*** NOTE — This assumes that if only one joint is inflamed, we’ve ruled out the possibility of Septic Arthritis.
More Common | Less Common |
---|---|
* Osteoarthritis * Gout * Pseudogout * Psoriatic Arthritis * Lyme Arthritis * Rheumatoid Arthritis | * Reactive Arthritis * Sarcoidosis (esp. both ankles) * Behรงetโs Syndrome * Stillโs Disease (Adult) * Inflammatory Bowel Disease * Avascular Necrosis (hip) |
Diseases Diagnosed and Treated by Generalist Clinicians
Most Common Causeย —ย Osteoarthritis (a.k.a. Degenerative Joint Disease [DJD])
- Elderly (usually begins >60 y.o.)
- Develops very gradually
- Almost never causes acute pain or flares
- Mostly knees, hips, fingers, feet, and spine
- Easily diagnosed by X-Ray
Gout and Pseudogout cause recurrent Attacks (or Flares)
KNEE — Aspirate joint to diagnose Gout or Pseudogout. Examine fluid for:
- Crystals — need special polarizing microscope to distinguish between the two
- White Blood Cell counts — in case there’s really a Septic Arthritis.
- Gram Stain & Culture — in case there’s really a Septic Arthritis.
X-Ray can sometimes identify Pseudogout
Note:ย Lots of swollen knees are really bursitis, not true arthritis (joint disease).ย See Monoarticular Arthritis — Full Text, see also Musculoskeletal Pains.
BIG TOE — Probably Gout. Hard to aspirate. Order blood test for Uric Acid, but beware:
- Many people whoโll never get gout have a high uric acid
- Up to 40% of Gout sufferers may have a normal uric acid during attack
- Best time to check uric acid: >2 weeks after the attack completely gone
ANKLE — Same as Big Toe.
- New arthritis in both ankles together suggests Sarcoidosis (diagnose by chest x-ray)
HIP — Usually Osteoarthritis
- Rarely Avascular Necrosis (bone death loss of blood supply) from alcoholism, chronic steroids, Sickle Cell, Lupus, advanced HIV, others (including some just in children)
- May be seen on X-ray; MRI is better
- Refer to Orthopedist for surgery
Referral to Rheumatology
Most types of Arthritis are diagnosed by Clinical Clues, NOT by lab tests or x-rays
- Rheumatologists have the experience
- Still, same labs as for Polyarthritis (which may begin in one or few joints)
- Joint x-rays to look for destruction
Clinical Clues for diagnosing Monoarticular or Oligoarticular Arthritis
** History of Flares — Patterns & duration of recurrences are key:
- First Toe, lasting 1-2 wks: Gout
- Knee: Gout or Pseudogout
- Behcetโs Syndrome flares with ulcers in genitals &/or mouth, lasts 1-3 weeks
- Late Lyme Arthritis may occur on and off (esp. the knee)
** Psoriasis — Diagnose Psoriatic Arthritis if also has Psoriasis
- silvery-white scaly plaques (usually backs of the elbows, fronts of the knees, scalp, Achilles tendon, or sacrum), PLUS:
- Finger arthritis in the far joint
- Nail pits
- โSausage Digitsโ (fingers / toes that taper at the ends)
** Age >65 at Onset — Pseudogout
- Usually involves the knee
- May cause as intermittent flares
- May look like chronic osteoarthritis in joints where that disease would be very unusual (knuckles, wrists, elbows, shoulders)
** Oral / Genital Ulcers — Behรงetโs Syndrome
- Arthritis tends to occur during ulcer flares
- Medium-sized joints: knees, ankles, wrists
- Turkish descent, or ancestors from the โSilk Roadโ (Arabic Peninsula on through Iran & the Indian subcontinent, to China-Korea-Japan)
** History of Diarrhea (chronic / bloody) — Inflammatory Bowel Disease
- Arthritis / Arthralgias tends to occur early in disease
** Recent Bacterial Diarrheal Infection or Genital Chlamydia — Reactive Arthritis
- Infection occurred days to weeks before arthritis
- Large / medium joints usually
- Also swelling at heel
- Keratoderma blennorrhagica — thick, scaly plaques on palms / soles
** Lived in Lyme Disease area — we’d wonder about Late Lyme Disease
- Visible swelling (knee, shoulder, ankle, elbow, wrist, TMJ)
- <5 joints; NOT symmetrical
- History of attacks lasting weeks – months
- Positive blood test for Lyme Antibody IgG [including confirmation with Western Blot]. A hard diagnosis, since many people who live in Lyme Disease areas have positive blood tests without any symptoms or complications (most people get cured on their own)
** Eye Disease (Painful: iritis, uveitis, episcleritis, scleritis) — we’d consider various possibilities
** Dactylitis (โsausage digitsโ) — we think:
** Enthesitis (inflammation where tendon/ligament meets bone) [esp. heel] — we think:
** Erythema Nodosum (painful red nodules on shins) — we think:
** Intermittent Fevers (lasting โฅ1 week) — we think Stillโs Disease
- salmon-colored maculopapular rash may come & go during fever
See Joint Pain: Just One / Few Joints — Full Text for more in-depth explanations and discussions