Psoriatic arthritis (PsA) is a progressive autoimmune disorder that can lead to permanent and debilitating joint damage. Like psoriasis, it is characterized by chronic inflammation. In PsA, immune cells are activated and produce too much of certain proteins which lead to the chronic inflammation. These proteins can cause skin cells to grow too quickly, leading to inflamed skin and other symptoms of psoriasis. The proteins also cause inflammation of the joints, which can lead to pain and progressive joint damage.
PsA presents differently depending upon the person with variable rates of disease progression; however, there are several symptoms that are characteristic of the disease:
- Joint swelling, pain, stiffness, or tenderness
- Swollen fingers and toes
- Reduced range of motion in the joints
- Back and neck pain
- Changes to the nails, such as pitting
Joint swelling, pain, stiffness, or tenderness
PsA causes inflammation at the joints. In some cases, patients develop dactylitis, a swelling of the fingers or toes in a sausage-like formation.1 Dactylitis is seen in about 35% of people with PsA and is often called “sausage” digits, or sausage fingers and toes. This is a very painful and sometimes disabling problem which involves swelling of an entire finger or toe. Research has shown that dactylitis is due to swelling and inflammation of all the tissues within a digit including the joints, tendons, entheses and bone. This inflammation causes a range of different symptoms including:
- Joint stiffness – With the inflammation of PsA, joints become stiff, especially first thing in the morning or after a period of rest.2
- Redness of joint – Many people with PsA experience redness of the skin in the area of the affected joints.
- Heat at joint – The inflammation of PsA can also create a feeling of heat at the joint.
- Loss of range of motion – PsA can cause a noticeable loss to the range of motion of joints which can affect daily tasks of grooming, shopping, and other activities.
- Pain – The inflammation from PsA can cause extreme amounts of pain at the joints. Stress can worsen this, making people with PsA more sensitive to pain.
Tendon and ligament pain and inflammation
In addition to the joints, PsA can also inflame the attachment points of tendons and ligaments, called the entheses, causing enthesitis. This often appears at the heel as Achilles tendonitis or at the bottom of the foot as plantar fasciitis. Other tendons and ligaments may also be affected. Enthesitis is present in many common conditions such as tennis elbow, plantar fasciitis, and Achilles tendonitis. When these problems are occurring repetitively or in a chronic fashion that does not heal in a person with psoriasis, the diagnosis of PsA should be considered.
Back and neck pain
The spine can be involved in about 40 percent of people with PsA, but it is rare for the spine to be the only area involved in PsA. While the lower back is usually the part of the spine that experiences the most inflammation, and where a person with PsA is most likely to experience back pain, neck pain is often experienced as well.
Both back and neck pain will usually feel better with activity and worse with rest. Inflammatory back pain can frequently awaken those who suffer from this symptom from sleep at night.
Changes to nails
Nail changes can affect all or part of one or more of the nails, but most commonly occur on the fingernails. Some people with PsA, but not all, also have symptoms of psoriasis on the skin of their hands, finger, feet, or toes. People who have psoriatic nail changes may have PsA and plaque psoriasis at the same time.
Nail changes are often an early warning sign that someone with psoriasis may also develop PsA. Nail psoriasis can cause pain and create an inability to grasp small objects or perform daily tasks like tying shoelaces or buttoning clothes.
Pitting is a common nail change, which leaves small indentations on the surface of the nail. Lines or ridges can also appear on the nail. Some people may have nails that weaken, split or become brittle and crumble apart. Scaling between the nail and the nail bed can cause the nail to lift up and separate from its bed.
Fatigue – People with PsA often experience generalized fatigue. Fatigue may appear as extreme tiredness, difficulty keeping eyes open, or flu-like symptoms. Patients also reported symptoms such as lack of motivation and loss of appetite in conjunction with fatigue. Fatigue can be experienced very differently depending on the person. No two individuals’ experiences are the same, even for people that have the same underlying health condition, like PsA.
Eye Problems – People with PsA are somewhat are significantly more likely than the “average” person to develop eye problems (0.1% vs. 7-10%). Of the eye problems that people with psoriasis develop, the most common is Uveitis, which is an inflammatory disease process internal to the eyes (intraocular inflammation). Uveitis refers to a group of inflammatory diseases of the eye from various causes that produce swelling and destroy eye tissue. Symptoms of uveitis include vision loss which can range from slight to severe loss of vision.
Early treatment is important to reduce the risk of complications, and patients with eye pain, severe light sensitivity, or any change in vision should immediately see an ophthalmologist for examination.
Hearing Problems – Research has shown that nearly a third of people with PsA may experience hearing loss. Experts are not entirely sure about the cause or progression of damage to the inner ear but believe that it results from the chronic inflammation that is a hallmark of PsA. This damage to the inner ear may also cause balance problems or feelings of vertigo.
Progression of psoriatic arthritis symptoms
In some cases, people with PsA may experience only stiffness and pain initially without any other symptoms. The pain and stiffness may be intermittent, brief flare-ups of symptoms might appear to go away. Many people may think that their joint symptoms spontaneously have resolved.
PsA often begins in the distal joints, those farthest away from the core of the body, such as the joints in the fingers and toes. Musculoskeletal symptoms are often slow to develop and hidden. A rapid onset of PsA symptoms is also possible and is reported in about one-third of people with PsA.
The symptoms of PsA, which vary from person to person, can change in severity. Skin symptoms typically appear before the joints become involved, sometimes up to 10 years before any joint symptoms are noticed. The fact that joint symptoms sometimes unfold over time, can make PsA not only difficult to diagnose, it also masks the damage that the chronic inflammation is causing in your body. Without treatment, many of these symptoms can lead to progressive, permanent joint damage. Arthritis mutilans, the most severe form of PsA, occurs in approximately 5% of people with PsA. The shortening of fingers and toes, deformity, and loss of function characterizes arthritis mutilans.
Once the diagnosis is made, a patient’s condition is characterized as mild, moderate or severe based on disease activity assessed in all five areas of involvement in PsA. These areas include the severity of skin disease, arthritis, back pain/spine involvement, dactylitis, and enthesitis. Sometimes your healthcare provider may use the term “active” PsA to mean that you are currently experiencing visible symptoms or experiencing pain or stiffness in joints. It is possible to experience periods of remission in PsA symptoms even if the symptoms have followed a progressive pattern of severity.