Poor prognostic factors include,

- Persistent synovitis

- Early erosive disease

- Extra-articular findings (including subcutaneous rheumatoid nodules)

- Positive serum RF findings

- Positive serum anti-CCP autoantibodies

- Carriership of HLA-DR4 "Shared Epitope" alleles

- Family history of RA

- Poor functional status

- Socioeconomic factors

- Elevated acute phase response (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP])

- Increased clinical severity.

When RA is clinically suspected, a physician may test for rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs measured as anti-CCP antibodies).

It is positive in 75-85%, but a negative RF or CCP antibody does not rule out RA, rather, the arthritis is called "seronegative", which is in about 15-25% of people with RA. During the first year of illness, rheumatoid factor is more likely to be negative with some individuals becoming seropositive over time. RF is a non-specific antibody and seen in about 10% of healthy people, in many other chronic infections like hepatitis C, and chronic autoimmune diseases such as Sjögren's syndrome and systemic lupus erythematosus. Therefore, the test is not specific for RA.

Hence, new serological tests check for anti-citrullinated protein antibodies ACPAs . These tests are again positive in 61-75% of all RA cases, but with a specificity of around 95%. As with RF, ACPAs are many times present before symptoms have started.

The by far most common clinical test for ACPAs is the anti-cyclic citrullinated peptide (anti CCP) ELISA. In 2008 a serological point-of-care test for the early detection of RA combined the detection of RF and anti-MCV with a sensitivity of 72% and specificity of 99.7%.

Other blood tests are usually done to differentiate from other causes of arthritis, like the erythrocyte sedimentation rate (ESR), C-reactive protein, full blood count, kidney function, liver enzymes and other immunological tests (e.g., antinuclear antibody/ANA) are all performed at this stage. Elevated ferritin levels can reveal hemochromatosis, a mimic of RA, or be a sign of Still's disease, a seronegative, usually juvenile, variant of rheumatoid arthritis.

Diagnosis of JIA is difficult because joint pain in children can be from many other causes. No single test can confirm the diagnosis, and most physicians use a combination of blood tests, X-rays, and clinical presentation to make an initial diagnosis of JIA. The blood tests measure antibodies and the rheumatoid factor. Unfortunately, the rheumatoid factor is not present in all children with JIA. Moreover, in some cases, the blood work is somewhat normal. X-rays are obtained to ensure that the joint pain is not from a fracture, cancer, infection, or congenital abnormality.

In most cases, fluid from the joint is aspirated and analyzed. This test often helps in making a diagnosis of JIA by ruling out other causes of joint pain.

Variations of the HLA-B gene increase the risk of developing ankylosing spondylitis, although it is not a diagnostic test. Those with the HLA-B27 variant are at a higher risk than the general population of developing the disorder. HLA-B27, demonstrated in a blood test, can occasionally help with diagnosis, but in itself is not diagnostic of AS in a person with back pain. Over 90% of people that have been diagnosed with AS are HLA-B27 positive, although this ratio varies from population to population (about 50% of African Americans with AS possess HLA-B27 in contrast to the figure of 80% among those with AS who are of Mediterranean descent).

The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), developed in Bath (UK), is an index designed to detect the inflammatory burden of active disease. The BASDAI can help to establish a diagnosis of AS in the presence of other factors such as HLA-B27 positivity, persistent buttock pain which resolves with exercise, and X-ray or MRI-evident involvement of the sacroiliac joints. It can be easily calculated and accurately assesses the need for additional therapy; a person with AS with a score of four out of a possible 10 points while on adequate NSAID therapy is usually considered a good candidate for biologic therapy.

The Bath Ankylosing Spondylitis Functional Index (BASFI) is a functional index which can accurately assess functional impairment due to the disease, as well as improvements following therapy. The BASFI is not usually used as a diagnostic tool, but rather as a tool to establish a current baseline and subsequent response to therapy.

Diagnosis is made by clinical examination from an appropriate health professional, and may be supported by other tests such as radiology and blood tests, depending on the type of suspected arthritis. All arthritides potentially feature pain. Pain patterns may differ depending on the arthritides and the location. Rheumatoid arthritis is generally worse in the morning and associated with stiffness; in the early stages, patients often have no symptoms after a morning shower. Osteoarthritis, on the other hand, tends to be worse after exercise. In the aged and children, pain might not be the main presenting feature; the aged patient simply moves less, the infantile patient refuses to use the affected limb.

Elements of the history of the disorder guide diagnosis. Important features are speed and time of onset, pattern of joint involvement, symmetry of symptoms, early morning stiffness, tenderness, gelling or locking with inactivity, aggravating and relieving factors, and other systemic symptoms. Physical examination may confirm the diagnosis, or may indicate systemic disease. Radiographs are often used to follow progression or help assess severity.

Blood tests and X-rays of the affected joints often are performed to make the diagnosis. Screening blood tests are indicated if certain arthritides are suspected. These might include: rheumatoid factor, antinuclear factor (ANF), extractable nuclear antigen, and specific antibodies.

Arthritis mutilans' parent condition psoriatic arthritis leaves people with a mortality risk 60% higher than the general population, with premature death causes mirroring those of the general population, cardiovascular issues being most common. Life expectancy for people with psoriatic arthritis is estimated to be reduced by approximately 3 years.

The bone edema in arthitis mutilans can be treated with TNF inhibitors in the short term: a 2007 study found that the bone edema associated with psoriatic arthritis (of which arthitis mutilans is a subtype) responded to TNF inhibitors with "dramatic" improvement, but the study was not determinative of whether TNF inhibitors would prevent new bone formation, bone fusion, or osteolysis (bone resorption).

There is no definitive test to diagnose psoriatic arthritis. Symptoms of psoriatic arthritis may closely resemble other diseases, including rheumatoid arthritis. A rheumatologist (a doctor specializing in autoimmune diseases) may use physical examinations, health history, blood tests and x-rays to accurately diagnose psoriatic arthritis.

Factors that contribute to a diagnosis of psoriatic arthritis include the following:

- Psoriasis in the patient, or a family history of psoriasis or psoriatic arthritis.

- A negative test result for rheumatoid factor, a blood factor associated with rheumatoid arthritis.

- Arthritis symptoms in the distal Interphalangeal articulations of hand (the joints closest to the tips of the fingers). This is not typical of rheumatoid arthritis.

- Ridging or pitting of fingernails or toenails (onycholysis), which is associated with psoriasis and psoriatic arthritis.

- Radiologic images demonstrating degenerative joint changes.

Other symptoms that are more typical of psoriatic arthritis than other forms of arthritis include enthesitis (inflammation in the Achilles tendon (at the back of the heel) or the plantar fascia (bottom of the feet)), and dactylitis (sausage-like swelling of the fingers or toes).

Some doctors include two other, less common forms: enthesitis-related arthritis and psoriatic JIA. Enthesitis is an inflammation of the insertion points of the tendons. This form occurs most often in boys older than 8, large joints of lower extremities are commonly affected; characteristically, it causes back pain, and is linked to ankylosing spondylitis and inflammatory bowel disease. Psoriatic JIA occurs most often in girls, in conjunction with psoriasis or any two of these features - i.e. dactylitit and nail pitting, although joint problems may precede the skin manifestations by several years.

FDG positron emission tomography (PET) may be useful to detect the condition early. Other imaging studies including MRI, CT scans, and X-rays may reveal inflammation and/or damaged cartilage facilitating diagnosis.

Several conditions can mimic the clinical presentation of psoriatic arthritis including rheumatoid arthritis, osteoarthritis, reactive arthritis, gouty arthritis, systemic lupus erythematosus, and inflammatory bowel disease-associated arthritis. In contrast to psoriatic arthritis, rheumatoid arthritis tends to affect the proximal joints (e.g., the metacarpophalangeal joints), involves a greater number of joints than psoriatic arthritis, and affect them symmetrically. Involvement of the spinal joints is more suggestive of psoriatic arthritis than rheumatoid arthritis. Osteoarthritis shares certain clinical features with psoriatic arthritis such as its tendency to affect multiple distal joints in an asymmetric pattern. Unlike psoriatic arthritis, osteoarthritis does not typically involve inflammation of the sacroiliac joint. Psoriatic arthritis sometimes affects only one joint and is sometimes confused for gout or pseudogout when this happens.

When faced with monoarthritis, one of the main decisions to make is whether to perform a "joint aspirate" by inserting a needle into the affected joint and removing some fluid for microscopic analysis. This decision is largely taken on inflammatory markers in blood tests (e.g. CRP), fever and the clinical picture. The main use of aspiration is to detect bacteria and neutrophil granulocytes (in septic arthritis) and crystals (crystal arthropathies).

There are several clinical criteria used to diagnose this disease. McAdam "et al." introduced the clinical criteria for RP in 1976. These clinical criteria have later been expanded by Damiani "et al." in 1979 and finally Michet "et al." modified them in 1986. See the following table for these diagnostic clinical criteria and the number of conditions required for an official diagnosis.

There is no known cure for either rheumatoid or osteoarthritis. Treatment options vary depending on the type of arthritis and include physical therapy, lifestyle changes (including exercise and weight control), orthopedic bracing, and medications. Joint replacement surgery may be required in eroding forms of arthritis. Medications can help reduce inflammation in the joint which decreases pain. Moreover, by decreasing inflammation, the joint damage may be slowed.

Assessment of Spondylarthritis International Society (ASAS criteria) is used for classification of axial spondyloarthritis (to be applied for patients with back pain greater than or equal to 3 months and age of onset less than 45 years). It is of two broad types:

1. Sacroiliitis on imaging plus 1 SpA feature, or

2. HLA-B27 plus 2 other SpA features

Sacroiliitis on imaging:

- Active (acute) inflammation on MRI highly suggestive of SpA-associated sacroiliitis and/or

- Definite radiographic sacroiliitis

SpA features:

- Inflammatory back pain

- Arthritis

- Enthesitis

- Anterior uveitis

- Dactylitis

- Psoriasis

- Crohn's disease or ulcerative colitis

- Good response to NSAIDs

- Family history of SpA

- HLA-B27

- Elevated CRP

Ultrasonography and magnetic resonance imaging of the hands and/or feet have been proposed as useful diagnostic investigations in RS3PE.

Some studies linked RS3PE to HLA-B27 whereas others have not.

Worldwide prevalence of spondyloarthropathy is approximately 1.9%.

Depending on the level of pain and damage suffered by a patient, a physician will recommend a treatment regimen that will relieve symptoms. Some of the most common recommendations include avoiding activities that make the pain worse, ice the knee for 20 to 30 minutes throughout the day to reduce inflammation, use over the counter anti-inflammatory medications, paracetamol (acetaminophen) and physical therapy.

Topical creams and patches can also be used for pain treatment and they have been proven to reduce pain by 33 to 57%.

Exercises can help increase range of motion and flexibility as well as help strengthen the muscles in the leg. Physical therapy and exercise are often effective in reducing pain and improving function. Working with a physical therapist to find exercises that promote function without risking further injury is effective for most patients. Many of the exercises used can be performed while sitting in a chair or standing in place. They are performed so that additional stress or weight is not placed on the knee joint. Water exercises are highly recommended along with the use of elastic bands.

Supportive devices like knee braces can be used. In most cases, the arthritis is centered on a single side of the knee, so braces are effective in providing stability to one side. Two different forms of braces are available. A support brace provides the aid the entire knee requires, where an up-loader brace shifts the pressure away from the specific part of the knee that is experiencing the pain. Shoes or inserts that are considered to be energy absorbing are found useful for some patients as well as walking devices like a cane. Shoe insoles that are fitted to correct flat feet have provided relief to many patients.

The use of oral steroids and anti-inflammatory medicines help to reduce the amount of inflammation and pain felt in the knee. If over the counter medicines like ibuprofen or naproxen are not strong enough, prescription strength medicines are used. If oral medicine and physical therapy don't help your knee enough, doctors may consider giving patients injections with pain medicine. Hyaluronic acid is present in the knee, but injections of it can be used to protect the joint when the cartilage becomes thinner and can't do it alone. These injections can provide more pain relief than oral medications lasting from six months to a year.

Surgery is the final option but may be required to relieve symptoms. Arthroscopy is performed through tiny cuts where damaged parts of the knee can be removed. Osteotomy is performed to reshape the bones in the knee and is only performed if one side of the knee is damaged. Arthroplasty is a replacement surgery where an artificial joint is used.

Low level laser therapy can be considered for relief of pain and stiffness associated with osteoarthritis.

Occurs in 5-10% of patients who have psoriasis.Classic presentation involves the DIP(distal inerphalangeal joints).Morning stiffness is present.Deformity of involved joints,dactylitis and nail involvement are common.Well demarcated red plaques with silvery scaling - the classic lesions of psoriasis are seen on the dorsum of the hand.

It is not always certain why arthritis of the knee develops. Most physicians believe that it is a combination of factors that can include muscle weakness, obesity, heredity, joint injury or stress, constant exposure to the cold, and aging. Cartilage in the knee begins to break down and leaves the bones of the knee rubbing against each other as you walk. Persons who work in a place that applies repetitive stress on the knees are at a high risk of developing this condition. Bone deformities increase the risk for osteoarthritis of the knee since the joints are already malformed and may contain defective cartilage. Having gout, rheumatoid arthritis, Paget's disease of bone or septic arthritis can increase your risk of developing osteoarthritis.

Some physicians and most podiatrist believe that Pes Planus (flat feet) cause increased rates and earlier incidence of knee osteoarthritis. In a study of army recruits with moderate to severe flat feet, the results showed that they had almost double the rate of knee arthritis when compared to recruits with normal arches.

Diagnosis is simple; usually a doctor can diagnose shoulder arthritis by symptoms, but they may ask for an x-ray or MRI for confirmation.

No specific work up is defined. Stenosing tenosynovitis is a clinical diagnosis. However, if rheumatoid arthritis is suspected, laboratory evaluation of is granted (e.g. rheumatoid factor). Imaging studies are not needed to diagnose the condition. However, they can be valuable adjuvants to achieve a diagnosis. An ultrasound or MRI ( the most reliable study) can demonstrate increased thickness of the involved tendons. Thickening and hyper-vascularization of the pulley are the hallmarks of trigger fingers on sonography.

RS3PE responds excellently to low dose corticosteroids, with sustained and often complete remission. Non-steroidal anti-inflammatory drugs (NSAIDs) have also been used. Hydroxychloroquine has proven effective in some cases.

CMC OA is diagnosed based on clinical findings and radiologic imaging.