Glossary of Psoriatic Arthritis Terms

Reviewed by: HU Medical Review Board | Last reviewed: February 2024 | Last updated: February 2024

This glossary covers some key aspects of psoriatic arthritis (PsA). Learning these terms can help you to better understand the condition.



Inflammation of the joints causing pain, swelling, and stiffness.1

Arthritis mutilans

The most severe form of PsA. Although rare, arthritis mutilans can lead to rapid joint destruction, deformity, and loss of function in the affected fingers or toes.1


A condition in which the body's immune system mistakenly attacks its own cells, tissues, or organs as if they were foreign invaders. This leads to inflammation and damage. In PsA, the autoimmune response contributes to joint inflammation and other symptoms.2



Medicines that target specific parts of the immune system to reduce inflammation.1



Signaling proteins in the immune system that regulate inflammation and immune responses. People with PsA overproduce certain cytokines. This adds to the inflammatory process and leads to joint inflammation, pain, and damage. Medicines targeting these cytokines are often prescribed to manage PsA and relieve symptoms.1



Inflammation and swelling of an entire digit, such as a finger or toe. It is a condition commonly seen in PsA. Dactylitis leads to a sausage-like appearance of the affected finger or toe and is often called “sausage fingers.”1,3

Disease-modifying antirheumatic drugs (DMARDs)

DMARDs are a type of medicine that works with the immune system to reduce inflammation and slow down the progression of PsA. They help prevent joint damage and improve overall symptoms.1



Inflammation of the points where ligaments or tendons attach to the bone, often causing pain and tenderness.1,3



A sudden and severe increase in symptoms like joint pain and swelling.1


Immune system

The body's defense mechanism against infections and diseases. In people with PsA, the immune system mistakenly attacks healthy joints and tissues. This leads to inflammation and joint damage.1


The body's natural response to injury, infection, or irritation. As the immune system works to heal and protect the affected area, redness, swelling, heat, and pain may occur. Inflammation plays a central role in PsA symptoms and joint damage.1


Joint erosion

Damage to the bones in the joints over time.4

Joint replacement surgery

Surgically removing a damaged or diseased joint and replacing it with an artificial joint, typically made of metal or plastic. This procedure is often considered for people with severe joint damage, such as from advanced stages of PsA. Joint replacement surgery can relieve pain and improve joint function.5



A type of medicine used to treat inflammatory conditions, including PsA.1


Nail psoriasis

Psoriasis that affects the nails, causing changes in color, shape, and texture.1,6

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Over-the-counter medicines used to relieve pain and reduce inflammation.1



A skin condition that causes red, scaly patches. PsA affects about 1 in 3 people with psoriasis.1,6

Psoriatic arthritis

A type of inflammatory arthritis that affects some people with psoriasis, causing joint pain, swelling, and stiffness. It can also involve other symptoms such as nail changes and inflammation of the points where ligaments or tendons attach to the bone (enthesitis).1,2,6



A period when symptoms are minimal or absent.4


A doctor who specializes in the diagnosis and treatment of conditions affecting the joints, muscles, and bones. They treat inflammatory and autoimmune disorders such as PsA.6



Inflammation of the spine, causing stiffness, pain, and potentially leading to fusion of the spine. Spondylitis limits flexibility and mobility. It is also called spondyloarthritis.1,2


Inflammation of the synovial membrane, the lining of a joint. It leads to pain, swelling, and stiffness.1,2


Tender points

Specific areas of the body that are painful to touch.1



Inflammation of the uvea, the middle layer of the eye. It can cause eye redness, pain, and sensitivity to light.1,2

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