Introduction (to all types of Joint Disease)
[Scroll down a little for this specific topic: Pain in just one, or a few, joints]
Joint Disease. We say “arthritis” when there’s evidence of inflammation, like joints are red, hot, & swollen, OR if we see destruction on x-ray. We say “arthralgia” if there’s only joint pain. Arthralgias can be due to a type of arthritis, destructive or not, but they may also (even more commonly) be due to viruses or other conditions which will go away without consequence. Even diseases with inflammatory arthritis don’t always cause permanent damage.
FIRST STEP — We determine that the patient’s pain is coming from joints (where bone meets bone), and not muscles (like Fibromyalgia). We also rule out conditions around the joint, like bursitis, tendonitis, bone disease, or conditions caused by nerve damage. See our topic on distinguishing among Musculoskeletal Disorders.
NEXT — Let’s say, from now on, we’re dealing with the actual joints. We identify the pattern of involvement, which includes:
- One Joint: (Monoarticular: “mono” = “one”, “articular” = joint)
- A Few Joints: (Oligoarticular: “oligo-” = “few,” like oligarchy)
- Many Joints: (Polyarticular: “poly” = “many”)
- Small joints: Wrists-hands-fingers / Ankles-feet-toes
- Large joints: Shoulders-elbows / Hips-knees
- Symmetric (pretty much similar pattern on right & left) vs. Asymmetric
- Migratory (leaves one joint, moves to another)
Overall, there are 2 broad types of arthritis:
- Inflammatory auto-immune diseases (rheumatoid arthritis, lupus, scleroderma, etc.), which can occur at any age & affect a variety of organs besides the joints
- Degenerative arthritis, a.k.a. Osteoarthritis, due to wearing out of joints with age (usually occurs >60 y.o.). There are no other complications apart from the affected joint itself. By the way, inflammatory arthritis can cause complete destruction of a joint that it becomes osteoarthritic.
KEY QUESTION — “Does the pain or stiffness hurt worse when you wake up in the morning, or get worse with use as the day goes on?”
- Early morning pain or stiffness lasting >30-60 minutes, that gets better with use as the joints loosen up, practically guarantees an inflammatory disease of one sort or another
No such pain in the morning, pain begins gradually during the day: NOT an inflammatory joint disease (most likely muscle pain, tendon strain, bursitis, etc.). See Musculoskeletal Disorders.
The topic here addresses pain in just one joint (Monoarticular Arthritis) and/or pain in just a few joints Oligoarthritis (usually larger ones like shoulder, elbow, hip, knee).
For pain in many joints, including wrists, hands, ankles, and/or toes (Polyarthritis) — see our topic Joint Pain — Many Joints. For Spine Pain — see topics Back Pain and Neck Pain
This section discusses joint pain that affects just one joint (Monoarticular). But before we go on, we have to think about the one uncommon but absolutely-worst-case possibility:
A single joint that became acutely red, hot swollen, tender, and painful, might be a Septic Arthritis (aka Septic Joint). This means infected with bacteria (usually Staph), which can completely destroy the joint, & spread to the bloodstream. If suspicious, in an ER they can aspirate fluid from it, start IV antibiotics, get preliminary results immediately, and if those seem positive, then admit to the hospital (to continue treatment 2-3 days until cultures show for sure if there are bacteria or not).
But the ER would want good reason. Knee aspirations are easy; other joints depend on the skills and interests of clinicians. For the hip, specialized interventional radiologists who know procedures can aim the needle into the joint by using fluoroscopy or ultrasound [certainly the latter in children]. So it’s not always easy to aspirate a joint, even though the results are crucial.
Most patients with Septic Arthritis have fevers (except the very old). The joint usually looks swollen & feels warm to touch. A generalized sense of feeling ill overall makes infection more likely, especially if there are drenching sweats.
The vast majority of patients with Septic Arthritis have a risk factor:
|* Age >80|
* Rheumatoid Arthritis
* Known chronic joint disease
|* Skin Infection|
* Prosthetic (artificial) Joint
|* Recent joint surgery|
* Recent steroid injection
* Injection Drug Use
Gonorrhea is a type of septic arthritis, more common in women than men. We suspect it if symptoms began shortly after a menstrual period. It most commonly occurs in the knee, followed by ankle and wrist. An ER will obtain cultures from joint fluid if possible, also from blood, and especially the cervix, rectum, and/or throat (depending on sex practices; people usually have no symptoms where Gonorrhea actually entered the body). Diagnosis is often made by response to treatment, since cultures may well be negative.
Other germs besides bacteria can cause septic arthritis (see link for a brief discussion of the varied types of germs that can infect us). They include fungi, and tuberculosis. When joint fluid is aspirated, we may order cultures for these as well as bacteria. But until results are back, we treat for bacteria, which are the most destructive & dangerous. Oftentimes, the number of white blood cells in joint fluid can give a good clue as to whether there are bacteria or not.
If the patient remembers previous episodes of similar symptoms, perhaps in another joint, it would seem like we’re not dealing with a new illness. However, joints injured from long-standing Rheumatoid Arthritis are prone to infection; also those with Gout, Pseudogout, Osteoarthritis, and Psoriatic Arthritis.
Confusion Is Easy
Most swollen joints are not septic arthritis; in fact, they’re usually not joint disease at all, but conditions such as bursitis or tendonitis. Basically — we confirm it’s the joint by finding “tenderness with Passive Range of Motion (PROM)” [“passive” means the examiner moves a limp, relaxed joint, as opposed to “active” ROM performed by the patient themselves]:
- With patient well-relaxed, we support the limb, and gently wiggle the joint.
- Wiggle it more.
- If we can move the joint through any of the ROMs, true joint disease is very unlikely.
It needn’t be complete ROM. For example, bending a knee that’s swollen from bursitis will hurt due to simple pressure. But then, if there’s no tenderness as we straighten it out, we’re probably not dealing with joint disease (because both bending & straightening move the joint, & thus should hurt). When a joint is infected, any degree of even passive movement in any direction is painful.
CAUTION: Red, hot, swollen, tender “joint” may be a skin infection (Cellulitis) — not something we’d want to advance a needle through into sterile joint. That would cause joint infection. So:
- We perform the same maneuver above to confirm it’s the joint. With cellulitis, stretching the skin in one direction may be tender, but not the opposite ROM.
- We lightly palpate and wiggle the skin: if that’s tender, the infection is likely superficial.
- If we tap on, pound on the joint, or jar it, and that hurts, we worry more about Septic Arthritis. If we can pound on the joint without causing pain (being careful to avoid the spot that’s red & hot), it’s probably not a joint infection.
- Septic hips may be too deep to be noticeably red or hot.
See our topic on general Musculoskeletal Pain for distinguishing among the various structures.
When a patient comes to us with a new, acute, very swollen & painful joint, we inquire about trauma, which could cause blood in the joint (Hemarthrosis). If a patient who awakens with monoarticular joint swelling happened to be drunk or high the night before, they may not remember the injury. We also suspect Hemarthrosis in patients taking anticoagulant medications, or with bleeding disorders (especially hemophilia, a genetic disease).
Now, back to Monoarticular Arthritis in general. Actually, once we’ve ruled out Septic Arthritis, we deal with the same diseases that might also affect a few joints instead of just one. So let’s address our topic Monoarticular / Oligoarticular Arthritis.
MONOARTICULAR / OLIGOARTICULAR ARTHRITIS
A number of diseases can affect a few joints, or just one joint, or sometimes one joint at one point in time and another at another. Also, to repeat ourselves, we’re discussing true joint pains, not pain from tendons, bursa, ligaments, muscles, etc. (see the section “Confusion Is Easy” under “Monoarticular Arthritis” above, and also our separate topic Musculoskeletal Pain). The following table outlines the causes that we distinguish among. (If just one joint is involved, be sure to note the asterisks ***).
Causes of Monoarticular *** / Oligoarticular Arthritis
*** NOTE — This assumes if only one joint is inflamed, we ruled out the possibility of Septic Arthritis.
|More Common||Less Common|
* Psoriatic Arthritis
* Lyme Arthritis
* Rheumatoid Arthritis
|* Reactive Arthritis|
* Sarcoidosis (esp. both ankles)
* Behçet’s Syndrome
* Still’s Disease (Adult)
* Inflammatory Bowel Disease
* Avascular Necrosis (hip)
Far and away, the most common cause of arthritis in just one or a few joints is Osteoarthritis (also called Degenerative Joint Disease, or DJD). It’s a condition of the elderly (usually begins >60 y.o.), develops very gradually, and primarily affects the knees, hips, fingers, feet, and spine. It hurts pretty much the same all the time, and almost never causes acute pain, or sudden severe flares, like any inflammatory arthritis does. However, every cause of inflammatory arthritis can destroy the joint over time to cause Osteoarthritis.
From now on, let’s say we’re dealing with acute joint pains, usually somewhat recent. This will wind up being a type of inflammatory arthritis (acute pain).
Specific Joint Involvement may guide us for Monoarticular Arthritis:
KNEE — Here, aspirating joint fluid (not difficult in this joint) is the key to diagnosing Gout or Pseudogout. Both commonly affect the knee. We have the fluid examined for:
- Crystals — Distinguish Gout from Pseudogout from Neither by a use of a special polarizing microscope. This is the main & best way to prove diagnosis 100%.
- White Blood Cell counts — Get results ASAP, because if heading toward 100,000 WBCs, or >75% “neutrophils” (a type of WBC), we missed a septic joint.
- Gram Stain & Culture — It would be really bad not to obtain these if the joint wound up having been infected.
BIG TOE — Few clinicians are able to aspirate this joint. Most of us assume an acutely inflamed Big Toe is Gout, and order a Uric Acid blood test for confirmation. However:
- Many people who’ll never get gout have a high uric acid
- Up to 40% of Gout sufferers may have a normal uric acid during an attack
- The best time to obtain the uric acid is >2 weeks after the attack has completely subsided
A typical attack of Gout lasts around a week, resolves on its own, & eventually recurs. The most common joints initially are first toe, knee, perhaps ankle. Any other pattern of “gout” should make you question the diagnosis (unless the disease has become chronic).
To diagnose for sure, a Rheumatologist needs to aspirate joint fluid during an attack.
ANKLE — Just like the Big Toe — probably Gout. New acute ankle arthritis in both ankles together suggests Sarcoidosis.
- For Sarcoidosis, we order a Chest X-ray to look for “hilar adenopathy” (large central lymph nodes)
- For Gout, we diagnose & treat as we did for the Big Toe
HIP — The most common cause of arthritis of the Hip joint is Osteoarthritis, which mainly occurs in older age. Younger patients should have tests for other diseases that eventually affect more joints (see below). An X-ray is usually enough to diagnose or rule out Osteoarthritis.
A much rarer condition, Avascular Necrosis, occurs when bone in the hip loses its blood supply. This only occurs in certain conditions: alcoholism, chronic steroid use, Sickle Cell, Lupus, previous fractures, previous decompression illness in scuba divers, advanced HIV or AIDS, & some other rare diseases (including some just in children). An X-ray can often make the diagnosis, but early on, an MRI is better.
Tests for Monoarticular or Oligoarticular Arthritis
We order many of the same tests as for polyarthritis, because occasionally those conditions begin with only one or few joints involved (see that topic for more explanation):
- Rheumatoid Factor (RF) Antibody — Rheumatoid Arthritis
- Antinuclear Antibody (ANA) — for Lupus and other diseases that usually cause Polyarthritis
- Hepatitis B surface Antigen (HBsAg) — for Chronic Hepatitis B
- Hepatitis C Antibody (HepC Ab) — for Hepatitis C
- Uric Acid — for Gout (best to obtain >2 weeks after attack has subsided)
- Complete Blood Count (CBC) for Anemia of Chronic Disease (with normal-sized blood cells, not small pale ones we see with low iron), cluing us in to a likely inflammatory condition
- Erythrocyte Sedimentation Rate (ESR, “Sed Rate”) — suggests inflammatory disease
- C-Reactive Protein (CRP) — A substitute for the ESR.
- Kidney function tests — mainly the blood tests Creatinine & BUN
- Urinalysis — Protein in the urine may point to Lupus.
We often request joint X-rays:
- Pseudogout has diagnostic findings that the radiologist will mention
- If “joint erosions” are found, it’s very important, since they a) narrow the diagnosis, and b) will destroy the joint if we don’t diagnose and treat appropriately. With erosions, we think especially of Rheumatoid Arthritis.
- Diagnoses Gout and Pseudogout for sure. Also the Septic Joint.
- Not so helpful with other types of arthritis
Clinical Clues for Monoarticular or Oligoarticular Arthritis
For oligoarthritis, or monoarticular arthritis of hip, arms, or hands, the above tests may not help. Even the ESR / CRP may be normal, despite the fact that inflammation is occurring. So we have to seek other clinical clues. Most of the diseases listed below often cause arthritis / arthralgias, but may be more well-known for other symptoms:
** History of Acute Flares — Patterns & duration of recurrences are key:
- Inflammation of Big Toe, lasting 1-2 wks: Gout
- Same for knee: Gout or Pseudogout
- Behcet’s Syndrome: flares with ulcers in genitals &/or mouth, lasts 1-3 weeks
- Late Lyme Arthritis may occur on and off (esp. the knee)
** Psoriasis — In 85% of people with Psoriatic Arthritis, psoriasis of the skin occurs before the joint. But sometimes patients don’t realize they have the condition. The best places for us to look for subtle silvery-white scaly plaques of psoriasis are on the backs of the elbows, fronts of the knees, the scalp (esp. at the hairline), the Achilles tendon, and the sacrum. If we see psoriasis, you’ll have clinched the diagnosis if we also find any of the following:
- Finger arthritis in the far joint
- Nail Pits
- “Sausage Digits” (fingers / toes that taper at the ends) (medical term is “dactylitis”) [also occur with Reactive Arthritis & Sarcoid]
** Age >65 at Onset — we think of Pseudogout
- Usually involves the knee
- May cause as intermittent flares
- May look like Osteoarthritis (chronic Degenerative Joint Disease) in joints where that disease would be very unusual (knuckles, wrists, elbows, shoulders)
** Oral / Genital Ulcers — It’s likely Behçet’s Syndrome
- Arthritis tends to occur during ulcer flares
- Medium-sized joints: knees, ankles, wrists
- Turkish descent, or ancestors from the “Silk Road” (Arabic Peninsula on through Iran & the Indian subcontinent, to China-Korea-Japan)
** History of Diarrhea (chronic / bloody) — we think maybe Inflammatory Bowel Disease (IBD)
- Arthritis / Arthralgias tends to occur early in disease
- If IBD has never been diagnosed, refer to Gastroenterologist for colonoscopy
- Whipple’s Disease causes arthritis + diarrhea + abdominal pains + weight loss. Among the rarest diseases of all! (ask a Rheumatologist, if all above symptoms present)
** Recent Bacterial Diarrheal Infection or Genital Chlamydia — we think Reactive Arthritis
- Infection occurred days to weeks before arthritis
- Large / medium joints usually (shoulder, elbow, hip, and/or knee)
- Enthesitis — 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). Knee is most common.
- <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). A negative IgG antibody rules out the disease.
** Eye Disease (painful: iritis, uveitis, episcleritis, scleritis) — we’d consider various possibilities
** Dactylitis (“sausage digit,” a fat, puffy finger / toe) — 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 ≥1 week) — we think Still’s Disease
- salmon-colored maculopapular rash may come & go during fevers
- Very rare. No test to diagnose. Send above symptoms to rheumatologist
Osteoarthritis (Degenerative Joint Disease) — As we’d mentioned above, this is the most common joint disease of all. It occurs in the relatively-elderly, onset is very gradual, there are no other “clinical clues” as above. X-Rays show joint space narrowing, lab tests are all normal.
The typical joints are hip, knee, fingers (not knuckles, except the at thumb), feet, and spine. Can occur in shoulders of people with long-term physical use (motorcyclists; jackhammering). Other joint patterns would be rare.
We refer these patients to Orthopedics, not Rheumatology, but only when they’re interested in surgery. However, I can recall 2 interesting patients:
A 54-year-old woman came to me from her Orthopedist for a pre-operative exam before knee replacement. Such severe osteoarthritis seemed strange for being only 54, worth a few more tests. Her ANA came back 1:320, Rheumatology diagnosed Scleroderma [& the Orthopedist still fixed her knee].
A 68-year-old woman developed acute onset of knee pain & swelling in Mexico. By the time she returned, it clearly wasn’t septic arthritis [she’d have died]. Blood tests were all negative, the Orthopedist operated for replacement. It was Osteoarthritis after all, because her other knee (no pain at all) looked almost as bad on X-ray.
And that’s it for Arthritis in one or just a few joints (or “Arthur-itis,” as some folks say).
See also Joint Pain: Just One / a Few Joints for the clinician’s condensed thought-process when face-to-face with a patient.