Adults only (18+)

What Are the 5 Types of Psoriatic Arthritis?

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis, a skin condition causing red, scaly patches. PsA affects the joints and areas where tendons and ligaments attach to bone, leading to pain, swelling and stiffness. It can present in several distinct patterns, often classified into five main types based on the joints involved and symptoms. Recognising these types helps guide diagnosis and treatment.

1. Asymmetric Psoriatic Arthritis

This is the most common form of PsA. It affects different joints on each side of the body and usually involves a few joints rather than many. The joints affected can include fingers, toes, knees or ankles. Unlike rheumatoid arthritis, which typically affects joints symmetrically, asymmetric PsA may cause uneven joint swelling and pain.

2. Symmetric Psoriatic Arthritis

Symmetric PsA resembles rheumatoid arthritis in that it affects the same joints on both sides of the body. It often involves small joints of the hands and feet and can lead to joint damage if untreated. Symmetric PsA tends to be more severe and may require aggressive treatment.

3. Distal Interphalangeal Predominant Psoriatic Arthritis

This type primarily affects the distal interphalangeal (DIP) joints, which are the small joints closest to the fingernails and toenails. It often causes nail changes such as pitting, ridging or separation from the nail bed. DIP involvement is characteristic of PsA and helps distinguish it from other types of arthritis.

4. Spondylitis (Axial Psoriatic Arthritis)

Spondylitis involves inflammation of the spine and the sacroiliac joints (located at the base of the spine). Symptoms include back pain, stiffness and reduced spinal mobility. This form of PsA overlaps with a related condition called ankylosing spondylitis and can cause significant discomfort and disability.

5. Arthritis Mutilans

This is a rare and severe form of PsA characterised by destructive inflammation that leads to bone resorption and joint deformity. It primarily affects the small joints of the hands and feet, causing severe disability if not treated promptly.

Summary

The five types of psoriatic arthritis include asymmetric, symmetric, distal interphalangeal predominant, spondylitis (axial), and arthritis mutilans. Each type affects different joints and has distinct features, influencing treatment approaches. Early diagnosis and tailored therapy are important to manage symptoms and prevent joint damage.