Psoriatic arthritis is a condition in which people with psoriasis — a skin disease characterized by itchy, red patches — also experience arthritis that leads to joint pain, stiffness, and inflammation. Although the arthritis is usually mild with occasional flare-ups, it can become continuous and potentially cause joint damage if untreated.
What is psoriatic arthritis?
Psoriasis is a skin disease that causes patches of itchy, red skin with a silver, scaly appearance. The lesions can occur on any part of the body, but common areas include elbows, knees, back, face, scalp, palms, and feet.
With psoriatic arthritis, people with psoriasis also have arthritis that causes pain, stiffness, and inflammation of the joints. Although the arthritis is typically mild with occasional flare-ups, in some people, it is continuous and can cause joint damage if not treated.
What are the signs and symptoms of psoriatic arthritis?
The signs and symptoms of psoriatic arthritis tend to vary from person to person. They can include any of the following:
- Psoriasis
- Swelling, stiffness, or pain in one or more joints
- Fatigue (i.e., frequently feeling tired or having a general lack of energy)
- ”Sausage-like” swelling of a whole finger or toe that is painful
- Changes in nails such as tiny dents, crumbling, or separation from the nail bed
- Eye inflammation that can cause pain, redness, and blurry vision
- Inflammatory bowel disease
How is psoriatic arthritis diagnosed?
There is no specific test for psoriatic arthritis, but physicians will evaluate the following to diagnose the disease:
- Family history of psoriasis or psoriatic arthritis
- Signs such as swollen and tender joints, psoriasis skin lesions, and changes in nails
- Blood tests to rule out other diseases with a similar presentation (e.g., rheumatoid arthritis, gout, Lyme arthritis)
- Changes in joints or the spine using imaging tests such as x-rays, magnetic resonance imaging (MRI), or ultrasound
What are some of the main medical treatments for psoriatic arthritis?
There is no cure for psoriatic arthritis, but treatments are effective for reducing disease symptoms and their severity. The treatments selected depend on the individual’s signs and symptoms and their severity. Often different medications are tried alone or in combination until the physician finds something that works.
Treatments for milder forms of the disease:
- Over the counter analgesics and anti-inflammatory medications to treat pain and swelling
- Corticosteroid injections into affected joints
Treatments for more severe forms of the disease:
-
Disease-modifying anti-rheumatic drugs (DMARDS, oral therapies that broadly suppress the immune system)
-
Biologic response modifiers (i.e., therapies that target specific immune signals to reduce disease activity)
Have any supplements been studied for psoriatic arthritis?
The efficacy of different supplements for improving symptoms or disease activity is unclear. There have been some pilot trials, but most of them have been limited by a small sample size, short duration, and/or lack of appropriate blinding.
The following supplements have been studied in preliminary trials for psoriatic arthritis:[1]
- Vitamin D
- Omega-3 fatty acids
- Primrose oil
- Gamma linolenic acid
- Coenzyme Q10, vitamin E, and selenium aspartate (in combination)
- Tripterygium wilfordii (i.e., thunder god vine)
- Paeony
- Curcumin
How could diet affect psoriatic arthritis?
In some people with psoriatic arthritis, eating certain foods seems to trigger symptoms,[2] and certain diets, such as gluten free, low carbohydrate and Paleolithic are popular among patients.[3] Fasting, vegetarian, and Mediterranean-style diets have also been evaluated in patients with psoriatic arthritis, but the overall quality of evidence is low.
Although the effect of different diet interventions is not clear, obesity is associated with significantly higher disease activity in psoriatic arthritis patients.[4] Thus, any diet leading to weight loss may be helpful for controlling disease symptoms.
Are there any other treatments for psoriatic arthritis?
Several small studies and case-reports have tested the effect of acupuncture on psoriatic arthritis, with overall positive results. Although high quality evidence is lacking, acupuncture is conditionally recommended by the American College of Rheumatology and the National Psoriasis Foundation.[5]
Exercise, yoga, stretching, and aqua therapy (because it tends to be easier on the joints to move around in water) are also helpful to improve overall health and to keep joints flexible.[6] Physical and occupational therapy can also help to strengthen muscles and increase flexibility, which can protect joints from further damage.
What causes psoriatic arthritis?
The cause of the autoimmune activity responsible for psoriatic arthritis pathology is not well understood. Both genetic and environmental causes have been implicated.
Research FeedRead all studies
Ketogenic and Mediterranean diets for psoriasis and psoriatic arthritis
In this randomized controlled trial, a ketogenic diet reduced psoriasis and psoriatic arthritis disease activity among adults with obesity. Both ketogenic and Mediterranean diets reduced weight, waist circumference, and fat mass.
Vitamin D levels in people with psoriatic arthritis
The role of diet and supplements on spondyloarthritis
Does a high-fiber/low-meat diet in autoimmune disease improve biologic drug treatment outcomes?
Omega−3s for improving bone and soft tissue turnover in psoriatic arthritis
Frequently asked questions
What is psoriatic arthritis?
Psoriasis is a skin disease that causes patches of itchy, red skin with a silver, scaly appearance. The lesions can occur on any part of the body, but common areas include elbows, knees, back, face, scalp, palms, and feet.
With psoriatic arthritis, people with psoriasis also have arthritis that causes pain, stiffness, and inflammation of the joints. Although the arthritis is typically mild with occasional flare-ups, in some people, it is continuous and can cause joint damage if not treated.
Is there a sex bias for psoriatic arthritis, similar to other autoimmune diseases?
Quick answer:
Unlike several other autoimmune diseases, psoriatic arthritis does not have a clear sex bias; some studies indicate similar incidence rates between men/boys and women/girls, whereas others suggest a higher incidence in men/boys. This variability may depend on the specific population in the study.
Many autoimmune diseases such as rheumatoid arthritis, Sjogren’s, and lupus have a female sex bias, meaning that they affect a disproportionate number of women compared to men. In contrast, whether or not there is a sex bias for psoriatic arthritis is less clear. Although some studies have reported that the incidence of psoriatic arthritis does not differ between males and females[14], this may depend on the population, as other studies have suggested that males may have increased incidence of the disease.[15]
What are the signs and symptoms of psoriatic arthritis?
The signs and symptoms of psoriatic arthritis vary among individuals and may include psoriasis, joint swelling, stiffness or pain, fatigue, "sausage-like" swelling of fingers or toes, nail changes, eye inflammation, and inflammatory bowel disease.
The signs and symptoms of psoriatic arthritis tend to vary from person to person. They can include any of the following:
- Psoriasis
- Swelling, stiffness, or pain in one or more joints
- Fatigue (i.e., frequently feeling tired or having a general lack of energy)
- ”Sausage-like” swelling of a whole finger or toe that is painful
- Changes in nails such as tiny dents, crumbling, or separation from the nail bed
- Eye inflammation that can cause pain, redness, and blurry vision
- Inflammatory bowel disease
How is psoriatic arthritis diagnosed?
Psoriatic arthritis is diagnosed through a combination of evaluating family history, physical signs like swollen joints and skin lesions, blood tests to exclude similar diseases, and imaging tests to assess joint or spine changes. There is no specific test for the condition.
There is no specific test for psoriatic arthritis, but physicians will evaluate the following to diagnose the disease:
- Family history of psoriasis or psoriatic arthritis
- Signs such as swollen and tender joints, psoriasis skin lesions, and changes in nails
- Blood tests to rule out other diseases with a similar presentation (e.g., rheumatoid arthritis, gout, Lyme arthritis)
- Changes in joints or the spine using imaging tests such as x-rays, magnetic resonance imaging (MRI), or ultrasound
Why is early diagnosis of psoriatic arthritis important?
Quick answer:
Early diagnosis of psoriatic arthritis is crucial because although some people may experience mild symptoms, others may face a more progressive and damaging disease course that can severely affect joint function and quality of life. A delay of 6 to 12 months in diagnosis can significantly increase the risk of long-term joint damage and disability.
Although psoriatic arthritis is only a mild disease in some people, in others, the disease course is more progressive and damaging, having a similar negative impact on joint function and quality of life as rheumatoid arthritis.[7] Even a 6–12 month delay in diagnosis can increase the possibility of long-term joint damage and disability.[8]
What are some of the main medical treatments for psoriatic arthritis?
Psoriatic arthritis has no cure, but effective treatments exist to reduce symptoms, and options vary based on individual severity. Milder cases may use over-the-counter medications and corticosteroid injections, but more severe cases may require disease-modifying antirheumatic drugs (DMARDs) and biologic response modifiers.
There is no cure for psoriatic arthritis, but treatments are effective for reducing disease symptoms and their severity. The treatments selected depend on the individual’s signs and symptoms and their severity. Often different medications are tried alone or in combination until the physician finds something that works.
Treatments for milder forms of the disease:
- Over the counter analgesics and anti-inflammatory medications to treat pain and swelling
- Corticosteroid injections into affected joints
Treatments for more severe forms of the disease:
-
Disease-modifying anti-rheumatic drugs (DMARDS, oral therapies that broadly suppress the immune system)
-
Biologic response modifiers (i.e., therapies that target specific immune signals to reduce disease activity)
Have any supplements been studied for psoriatic arthritis?
The efficacy of various supplements for psoriatic arthritis remains unclear due to limitations in pilot trials, such as small sample sizes and short durations. Some of the supplements studied include vitamin D, omega-3 fatty acids, primrose oil, and curcumin, among others.
The efficacy of different supplements for improving symptoms or disease activity is unclear. There have been some pilot trials, but most of them have been limited by a small sample size, short duration, and/or lack of appropriate blinding.
The following supplements have been studied in preliminary trials for psoriatic arthritis:[1]
- Vitamin D
- Omega-3 fatty acids
- Primrose oil
- Gamma linolenic acid
- Coenzyme Q10, vitamin E, and selenium aspartate (in combination)
- Tripterygium wilfordii (i.e., thunder god vine)
- Paeony
- Curcumin
How could diet affect psoriatic arthritis?
Certain foods may trigger symptoms in some people with psoriatic arthritis. Individuals report relief from following popular diets, including gluten-free, low carbohydrate, and Paleolithic diets. Although the effect of specific diets is unclear, weight loss through diet may help control disease symptoms because obesity is associated with increased disease activity.
In some people with psoriatic arthritis, eating certain foods seems to trigger symptoms,[2] and certain diets, such as gluten free, low carbohydrate and Paleolithic are popular among patients.[3] Fasting, vegetarian, and Mediterranean-style diets have also been evaluated in patients with psoriatic arthritis, but the overall quality of evidence is low.
Although the effect of different diet interventions is not clear, obesity is associated with significantly higher disease activity in psoriatic arthritis patients.[4] Thus, any diet leading to weight loss may be helpful for controlling disease symptoms.
Are there any other treatments for psoriatic arthritis?
Acupuncture has shown positive effects on psoriatic arthritis in small studies, and although high-quality evidence is lacking, it is conditionally recommended by the American College of Rheumatology and the National Psoriasis Foundation. Additionally, exercise, yoga, stretching, aqua therapy, and physical or occupational therapy can improve overall health, joint flexibility, and muscle strength.
Several small studies and case-reports have tested the effect of acupuncture on psoriatic arthritis, with overall positive results. Although high quality evidence is lacking, acupuncture is conditionally recommended by the American College of Rheumatology and the National Psoriasis Foundation.[5]
Exercise, yoga, stretching, and aqua therapy (because it tends to be easier on the joints to move around in water) are also helpful to improve overall health and to keep joints flexible.[6] Physical and occupational therapy can also help to strengthen muscles and increase flexibility, which can protect joints from further damage.
What causes psoriatic arthritis?
The exact cause of psoriatic arthritis is not well understood, but both genetic factors and environmental triggers (such as stress, obesity, infection, and injury) have been implicated in its onset. Many people with this condition have family members who also have it, which suggests a genetic link.
The cause of the autoimmune activity responsible for psoriatic arthritis pathology is not well understood. Both genetic and environmental causes have been implicated.
Are people with psoriasis at increased risk of developing psoriatic arthritis?
Quick answer:
Approximately 20% to 30% of people with psoriasis will develop psoriatic arthritis, although psoriasis may not always be easily detected, especially on the scalp or nails. Additionally, 10% to 15% of this population may develop arthritis before showing any signs of psoriasis.
What are the risk factors for developing psoriatic arthritis?
Quick answer:
The potential risk factors for developing psoriatic arthritis in people with psoriasis include corticosteroid use, pregnancy, trauma, rubella vaccination, smoking, infections that require hospitalization, heavy drinking, family history, and obesity. However, these associations are primarily based on observational studies, and their causative role remains unclear.
Although it isn’t easy to predict whether patients with psoriasis will develop psoriatic arthritis, some potential risk factors have been identified, including:[11]
- Corticosteroid use within 2 years of first developing psoriasis
- Pregnancy within 2 years prior to psoriasis onset[12]
- Trauma that required medical care[13]
- Vaccination against rubella[13]
- Smoking
- Infections requiring hospitalization
- Heavy drinking
- Family history of psoriatic arthritis
- Obesity
It is important to note that the above risk-associations were mostly found through case-control (observational) studies, so it isn’t yet clear whether they play a causative role in developing the disease.