Erosive osteoarthritis (EOA) is a rare condition involving cartilage damage and bone erosion to the hand’s finger joints. It is a more severe form of osteoarthritis (OA) and causes impaired hand function and abnormality.

OA of the hand is a common condition affecting the joints through wear and tear but limited inflammation.

In contrast, EOA is more aggressive and involves the top finger joints. The condition may be responsible for inflammatory changes to the synovial fluid and subchondral bone.

EOA can lead to hand abnormalities and impaired hand function, although people can control some of their pain symptoms. Medical professionals have only recognized EOA as a condition in the last 10 years, while research into treating this condition remains ongoing.

Read on to learn about EOA’s:

  • symptoms
  • causes
  • diagnosis
  • treatment
  • outlook
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Some people may mistake the onset of EOA symptoms for other conditions. Therefore, doctors may need to exclude these other diseases before reaching a definitive diagnosis of EOA. The main method of diagnosis consists of looking at a person’s symptoms.

Medical professionals do not all agree about differentiating regular OA from EOA, as the conditions develop in a similar way. Generally, EOA is more severe and may lead to bone erosions and tissue swelling.

Initial symptoms of EOA include:

  • fast onset of pain
  • swelling
  • warmth and redness in the affected joints
  • tingling fingertips
  • limited hand and joint function
  • stiffness of the hand
  • nodules or lumps on the fingers

X-rays or other tests may also show:

  • negative rheumatoid factor, an immune system protein that attacks healthy cells in the body
  • local inflammation to the affected joint
  • central bone erosions
  • bony growths called osteophytes
  • subchondral cysts, cysts in the bone below the cartilage
  • partial dislocations, or subluxations
  • bone fusion, or ankyloses
  • narrowing of joint spaces

Bone erosions can form the shape of a gullwing or sawtooth, a classic feature of this condition. EOA can also affect a person’s quality of life and their ability to work.

A 2019 study found that a significant number of people with an EOA diagnosis also had a first-degree relative — a biological parent, sibling, or child — with the same condition, suggesting that there may be a genetic component to the disease.

Other causes of EOA may include:

  • smoking
  • drug therapy
  • a lack of mobility
  • a loss of muscular strength due to age
  • menopausal hormone changes
  • a dysfunction of hormone systems, including thyroid or adrenal gland
  • inflammation or inflammatory disease, including rheumatic disease and irritable bowel syndrome

Risk factors for EOA include age and gender, while postmenopausal females are also at higher risk. Other risk factors may include genetics and the repetitive use of hands, often for work.

People with EOA are at higher risk for high cholesterol and the conditions for metabolic syndrome, including obesity, diabetes, and hypertension. Additionally, studies have begun to examine the link between EOA and the risk of heart conditions.

Patterns of joint pain, joint inflammation, and the types of affected joints are what doctors use to reveal whether a person has EOA.

The condition usually involves the tips of the fingers, which rarely feel the effects of rheumatoid arthritis (RA). For example, RA often affects the knuckle joints, which EOA does not impact, while the middle finger joints may be involved in either condition. Over time, EOA limits hand function and can cause hand abnormalities.

A healthcare professional will look at a person’s medical history and X-rays of the affected hand to find symptomatic bone erosions. An MRI or ultrasound may also help find soft tissue damage.

A doctor may take blood tests to eliminate RA and measure the erythrocyte sedimentation rate, which indicates the presence of inflammation in the body. The inflammation should be local to the joint instead of throughout the whole body.

Treating EOA focuses on relieving and controlling symptoms.

Research is ongoing into whether therapy targeting inflammation is effective. Treatments are similar to those for other forms of arthritis.


Doctors use nonsteroidal anti-inflammatory drugs (NSAIDs) to treat regular OA as a standard first-line treatment for EOA. NSAIDs include ibruprofen, naproxen, diclofenac and high-dose aspirin.

Steroid injections

Injecting steroids or corticosteroids in inflamed joints 3–4 times a year can help ease EOA symptoms temporarily. However, injecting the small joints may not be as effective and may be more painful.


The application of heat helps ease pain and inflammation when treating EOA.

Additionally, warming the joints can help with stiffness and range of motion and can alleviate pain.

Occupational therapy

Occupational therapy helps maintain the range and motion of joints. Experienced therapists can also suggest modifications or assistive devices to enable people living with EOA to manage their day-to-day living.

Additionally, maintaining hand function is an important part of EOA treatment. Occupational therapists can help with providing splints to support the joints and advice on living with the condition.

Disease-modifying antirheumatic drugs and biologics (DMARDS)

Researchers are studying whether DMARDS are effective against EOA.

However, current research states they are no more effective than placebos against EOA.

People may sometimes mistake the symptoms of EOA for other conditions. As such, doctors may need to exclude these conditions before diagnosing EOA.


Many of the symptoms are the same in both OA and EOA. However, OA can affect more joints than EOA.

EOA is also generally more severe in terms of damage to the joints. Some scientists consider EOA a subset of OA, while others consider EOA a separate condition from OA.


RA features a similar swelling of joints, while both conditions may involve synovitis, which is an inflammation of the synovial membrane, a membrane that lines the joint.

However, RA is likely to affect a variety of joints, and people with the condition may test positive for rheumatoid factor, which can attack healthy tissue. In contrast, people living with EOA will test negative for this.

Psoriatic arthritis

While psoriatic arthritis may have identical symptoms to EOA, it often accompanies psoriasis. For some people, the area where the skin condition appears is so small that it might not be noticeable or only develop on the scalp.

Psoriatic arthritis is more likely to cause swollen fingers and toes when there is swelling across the whole digit.

The condition will also cause finger and toenail changes where the nails turn crumbly and brittle.

There is currently no cure for EOA. Therefore, early diagnosis is important to preserve joints and functionality.

Research is ongoing to find effective treatments for the condition. Two recent studies have examined whether hydroxychloroquine or methotrexate might help with disease progression. The scientists used both drugs to help with autoimmune disorders, including RA. Researchers found that methotrexate might be able to halt the progression of joint damage to some extent, but further research is necessary.

People with EOA could also control their pain, but the condition may still progress to impair hand function and cause hand abnormalities. Research is ongoing to find an effective form of treatment.

EOM is a more severe form of OA that affects mainly the hands through the finger joints.

Postmenopausal females have a higher risk factor for this condition, while genetics may also be a factor. Doctors diagnose EOA by eliminating other possible conditions.

Treatment focuses on relieving symptoms, but it can be difficult to limit damage to the joints. Current therapies are ineffective in reducing joint damage, although research is ongoing to discover newer arthritis treatments that may help.

A person who suspects they may be developing EOA should speak with a healthcare professional as soon as they can to prevent the condition from progressing.