Psoriatic arthritis (PsA) and reactive arthritis (ReA) are different types of arthritis. PsA is a condition associated with the skin disease psoriasis, and ReA occurs in response to an infection. Although both conditions involve swelling and joint pain, they have different causes.

Arthritis is a condition that causes painful inflammation, swelling, and stiffness in the joints. PsA and ReA are two of more than 100 types of arthritis.

This article explains the similarities and differences between PsA and ReA. We examine their relative symptoms, symptom severity, and symptom duration. We also outline the different causes and treatments for each disease.

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While PsA and ReA are distinct arthritis types with different causes, they share some common symptoms.

Symptoms that may occur in both conditions include:

  • Joint and back pain: Both types of arthritis can cause inflammation, pain, and stiffness in the joints, particularly in the knees, ankles, hands, and feet. They can also affect the spine, causing pain and stiffness in the lower back and, for some people, spondylitis of the spine.
  • Enthesitis: PsA and ReA may develop enthesitis, inflammation of the points where tendons and ligaments attach to bones.
  • Dactylitis: Both conditions may cause inflammation of the fingers and toes, making them appear sausage-shaped.
  • Skin lesions: People with PsA or ReA may develop skin sores or patches of discolored skin.
  • Nail lesions: Some people with PsA or ReA develop issues with their nails.
  • Eye disease: In some cases, PsA or ReA can cause conjunctivitis. Conjunctivitis occurs when the eye’s lining, or conjunctiva, becomes swollen and inflamed. Symptoms include eye redness and a gritty sensation. Both conditions can also be associated with severe eye disease, such as anterior uveitis.

Psoriasis is a common skin condition. According to the National Psoriasis Foundation, psoriasis affects around 8 million people in the United States. It also states that about 30% of people with psoriasis have PsA, typically developing 10 years after psoriasis.

ReA, also known as Reiter’s syndrome, is rarer, affecting around 0.6 to 27 people in every 100,000.

The symptoms of PsA and ReA are similar, but some subtle differences exist.


Most people with PsA experience skin issues before developing joint symptoms. Areas of the skin may become red or discolored and covered in flaky scales.


Nail psoriasis may present as:

  • nail pits, which are small dents in the finger or toenails
  • discolored nails, which may appear white, yellow, or brown
  • crumbling nails
  • nails that separate from the finger or toe
  • bleeding beneath the nails

Eye disease

Some people with PsA develop lesions around the eyes, which can cause the following symptoms:

  • redness
  • dryness
  • discomfort
  • vision problems

People with PsA may develop uveitis, which happens when there is inflammation of the middle layer of tissue in the eye called the uvea. Uveitis occurs in around 7–20% of people with psoriasis and happens more often in people with psoriasis and PsA. Conjunctivitis is also a common eye problem associated with PsA.


When PsA affects the hands or feet, they can appear “sausage-like.” Dactylitis is the medical term for swelling of a finger or toe. Dactylitis does not occur symmetrically, meaning it can involve different fingers and toes on either side of the body.

The National Psoriasis Foundation notes that around 40% of people with PsA experience dactylitis. It results from inflammation of the small joints and enthesitis of the surrounding tendons.


ReA usually develops several days or weeks after a gut infection, urine infection, or sexually transmitted infection (STI). It most commonly affects the large joints of the lower limbs, such as the knees and ankles.

People may also develop inflammation of the urinary tract.


Thickening of the fingernails or toenails is common in people with ReA. People may also experience nail separation from the nail bed, nail scales accumulating under the nail, and nail pitting.

Eye disease

Conjunctivitis is common in people with ReA, and around 26% of people with ReA experience uveitis.

Conjunctivitis and uveitis may cause symptoms such as:

  • redness
  • swelling of the eyes
  • eye pain
  • blurred vision
  • sensitivity to light, or photophobia
  • eye crusting in the morning

The relative severity and duration of PsA and ReA is as follows.


The severity of PsA varies from person to person.

PsA occurs in 30% of people with psoriasis, for which there is no cure. However, medication and lifestyle changes can help to manage both conditions.


ReA can be mild or severe. Severe forms of the condition can significantly impact a person’s quality of life.

The symptoms of ReA can last around 3–12 months. During this time, the symptoms can come and go. Between 30–50% of people find that the condition returns later or becomes chronic.

The causes of PsA and ReA are different.


PsA is associated with psoriasis. Psoriasis is a common skin condition that affects around 2% of the population. Scientists do not know what causes psoriasis. However, it is an immune-mediated illness linked to a fault with the immune system.

Inflammation is a normal part of immunity. It helps to remove pathogens and other threats from the body. In psoriasis, skin inflammation develops and persists without such threats. PsA occurs when inflammation affects both the skin and joints.

Only 14.8% of people develop PsA before they have symptoms of psoriasis.


ReA occurs in response to a bacterial infection. The most common causes include:

  • STIs, such as chlamydia and gonorrhea
  • Salmonella enteritidis
  • Shigella
  • Campylobacter jejuni
  • Clostridium difficile

Some of the treatment options for PsA and ReA differ.


Treating PsA involves reducing joint inflammation and keeping psoriasis under control.

Treatment options include:

  • physical therapy to help improve joint mobility and alleviate pain
  • arthritis-friendly exercises to reduce joint pain and stiffness
  • resting when the pain flares or worsens
  • wearing braces, splints, and supports to protect the joints
  • taking nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen, or naproxen, to help alleviate inflammation and pain

In more severe cases, doctors may suggest prescription medicines, such as:

  • Celecoxib: A pain reliever and NSAID.
  • Corticosteroid injections: Anti-inflammatory medications that help to treat swollen and painful joints.
  • Methotrexate: An immunosuppressant that suppresses the immune system to reduce inflammation.
  • Injectable biologics: These medications block the activity of cells, chemicals, or proteins involved in inflammation.


To treat ReA, doctors usually recommend antibiotics to clear the underlying infection if there is evidence of an ongoing active infection. If the arthritis is chronic, there is no evidence that antibiotic treatment is helpful.

A doctor may also recommend the following treatments to help with arthritis pain:

  • physical therapy
  • orthotics and insoles
  • arthritis medications, such as methotrexate, sulfasalazine, and azathioprine

Doctors initially prescribe NSAIDS for acute arthritis. If pains persist, they may use oral or injectable corticosteroids. If conservative treatment is not working, doctors can also use conventional disease-modifying drugs such as sulfasalazine and methotrexate, followed by biologics if necessary.

PsA and ReA are forms of arthritis that involve joint pain and swelling. They have different causes.

PsA often occurs in people with psoriasis, while ReA occurs in response to an infection. Both conditions present similar symptoms but with subtle differences between the two.

The treatment approach to PsA and ReA differs, so a person should consult a doctor for an accurate diagnosis and treatment strategy.

People with PsA may need medications to control psoriasis, while those with ReA typically require treatment for the infection that triggered the disease. Treatment for both conditions may involve drugs to reduce joint pain and inflammation.