Psoriatic arthritis (PsA) is a type of inflammatory arthritis. When present in the shoulder, it may feel stiff and painful to move. People may also find it painful or difficult to lift their arms.
The body responds to this attack with inflammation, as if fighting an infection or injury. The area becomes hot, swollen, and sore, and the person may not be able to move their arm without pain.
This article explains what PsA is and how it may affect a person’s shoulder. It also explores treatment options and how lifestyle changes may help people living with this condition.
PsA is an inflammatory disease that affects a person’s joints and the places where bones connect with tendons and ligaments. According to the National Psoriasis Foundation (NPF), around 30% of people with psoriasis will develop PsA.
While there is no cure for PsA, doctors can recommend treatments to reduce a person’s pain and protect their joints from long-term damage.
Learn more about PsA.
PsA in the shoulder
The shoulder contains three bones and two joints. The upper arm bone, or humerus, and shoulder blade, or scapula, form a ball and socket joint, giving the arm a wide range of movement. The second joint connects the shoulder blade to the collarbone, or clavicle.
PsA can affect either or both of these joints and make it painful for a person to move their arm. Simple movements, such as brushing their hair or lifting objects, may increase the pain.
People may also find it difficult to sleep, especially if they roll onto a sore shoulder at night.
PsA can affect any joint in the body. According to the Arthritis Foundation (AF), it is most common in the fingers, wrists, knees, and ankles. When it affects a person’s fingers, it is known as dactylitis.
Occasionally, PsA affects a person’s spine and can make it difficult for them to bend. This condition, called spondylitis, may also make the person’s neck stiff.
Some people experience tenderness and swelling at the points where tendons and ligaments connect with bones. This is known as enthesitis.
PsA can also affect a person’s nails, making them crumble or lift away from the nail bed. Pitting and white spots on the nails are signs of PsA.
Most people with PsA in the shoulder feel pain when moving their arm. The shoulder area may also feel hot to the touch.
The American Academy of Orthopedic Surgeons (AAOS) explains that people may feel pain in slightly different areas, depending on which shoulder joint the PsA affects.
People with PsA in the glenohumeral joint, where the upper arm bone and shoulder blade meet, may feel pain in the side or back of their shoulder. They may experience an ache deep inside the joint.
If PsA targets the acromioclavicular joint, where the shoulder blade and collarbone join, the pain is more likely to be on top of the shoulder. Sometimes people experience pain in the neck or arms.
If the whole shoulder area is painful, it may indicate that PsA is affecting both joints.
Early warning signs of PsA
Any joint pain or stiffness may be a warning sign that someone with psoriasis is developing PsA, and it can affect multiple joints at the same time.
Many people with PsA in the shoulder find it difficult to sleep, especially if they prefer to sleep on the affected side. Their shoulder may ache more in the mornings.
Other early warning signs include:
- changes in the appearance of the nails
- foot pain, particularly in the heel or on the sole
- swollen, “sausage-like” fingers or toes
- digestive issues, such as bloating or diarrhea, if PsA affects the digestive tract
Learn more about the symptoms of PsA.
The exact causes of psoriasis or PsA are unknown, but doctors believe genetics may play a part.
The American College of Rheumatology estimates that around 40% of people with PsA have a family member with either psoriasis or arthritis.
Other known risk factors include:
- the severity of psoriasis, particularly if it is on the scalp or buttocks
- injury or trauma to the area
Doctors consider a person’s history of psoriasis and current aches and pains before diagnosing someone with PsA.
They may recommend blood and imaging tests to rule out other conditions and establish whether inflammation has damaged the shoulder joints.
Although there are no conclusive tests for PsA,
Learn more about diagnosing PsA.
People who have PsA may each experience it differently, and doctors plan treatments around the individual.
If someone’s symptoms are mild and short-lived, they may recommend anti-inflammatory medication and over-the-counter pain medication, which are available in drugstores.
If a person’s symptoms are severe, doctors
Other drug therapies include injections of corticosteroids to reduce swelling. However, the AAOS points out that these benefits are short-lived, and swelling can return.
Steroid use should be minimal in those with PsA, as tapering off steroids can cause psoriasis flare-ups.
While the person’s shoulder is inflamed and sore, the AAOS recommends icing it for around 20 minutes, three times per day. It also suggests resting the arm until the swelling subsides.
When the person can move their arm more freely, doctors may suggest exercises to support and strengthen the shoulder joint.
A doctor may also refer a person to a physical therapist to discuss an appropriate physical therapy program.
If a person’s symptoms are very severe, the shoulder joints are damaged, and other treatments have been unsuccessful, doctors may recommend surgery.
According to the AAOS, doctors can remove a part, or all, of the damaged bones. In severe cases where other interventions have not worked, a surgeon can replace the shoulder joints.
As well as following any exercise program doctors or physical therapists recommend, people can take steps to reduce their pain and inflammation.
- achieving and maintaining a moderate weight
- quitting smoking, if applicable
- reducing or eliminating alcohol consumption, if applicable
- eating a range of healthy foods, particularly those with known anti-inflammatory properties, such as oily fish, nuts and seeds, vegetables, and lean proteins
People may also consider changing their sleeping positions, to help support their shoulders during the night.
PsA is a chronic inflammatory condition that affects people with psoriasis. It can lead to swelling and tenderness in a person’s joints.
When it affects the shoulder, it can restrict a person’s range of movement, making it difficult to move the arm. Many people experience sleep problems, as the shoulder pain keeps them awake.
Although there is no cure for PsA, doctors can prescribe medications to reduce inflammation and offer lifestyle tips to help people manage their symptoms.