Psoriatic arthritis and psoriasis are types of psoriatic disease. Psoriatic arthritis causes joint pain and stiffness, and psoriasis mainly involves the skin, but they often occur together.
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Both conditions are long-term. Psoriasis does not worsen over time but becomes more troublesome during flares.
PsA can cause joint damage, leading to permanent damage. It often worsens over time, but the outlook will vary between individuals.
Treatment can relieve symptoms, enable remission, and slow disease progression.
This article explores the link between psoriasis and PsA. It also looks at the causes, symptoms, and treatments of each condition.
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Psoriasis and PsA are related, but they are separate conditions. They are part of psoriatic disease, an immune-mediated inflammatory condition.
Immune responses that lead to inflammation in the body cause the symptoms of both conditions.
- In plaque psoriasis, inflammation causes skin cells to renew too quickly, resulting in a scaly rash on the skin with characteristic silvery plaques.
- In PsA, inflammation causes joint pain and stiffness. It can affect one or more joints and may lead to long-term joint damage.
- In both conditions, a person may also have eye inflammation, known as uveitis, and pitted or crumbling psoriatic nails.
Psoriasis and PsA often affect the same people, but not always.
Experts do not know precisely how many people with psoriasis will develop PsA, but research has suggested it is between
Of these,
Meanwhile, some people have PsA without psoriasis.
Scientists believe that up to
The severity of psoriasis does not predict whether someone will develop PsA.
Both psoriasis and PsA can:
- cause discomfort
- affect a person’s quality of life
- affect their mental health and self-esteem
People with PsA, psoriasis, or both may also have a
Treatment for PsA and psoriasis can help ease symptoms and reduce the risk and severity of flares. Some treatments are similar, such as the use of biologic drugs. However, some target PsA or psoriasis specifically.
This table shows some similarities and differences between PsA and plaque psoriasis, the most common form of psoriasis.
| Plaque psoriasis and PsA | Plaque psoriasis only | PsA only | |
|---|---|---|---|
| Causes and risk factors | – inflammation – genetic factors – a history of psoriatic disease | – physical trauma to the skin | – a personal history of psoriasis, especially with nail psoriasis or uveitis – a family history: – psoriasis affecting a |
| Triggers | – stress – some medications – alcohol and tobacco use – infections that involve inflammatory processes | – physical trauma to the skin – exposure to sunlight – infections | – physical trauma to a joint – heavy lifting – infectious diarrhea |
| Common symptoms | – uveitis – nail psoriasis | – itchy, silvery plaques on the skin – other skin changes for other types of psoriasis | – joint pain and stiffness – swollen, or “sausage”, fingers or toes (dactylitis) – inflammation in tendons and ligaments where they meet a joint (enthesitis) – back pain (spondylitis or axial PsA) |
| Treatment | – systemic drugs, – various lifestyle remedies – counseling and treatment for mental health complications | – moisturizers and emollients – topical corticosteroids – other topical applications – light therapy – methotrexate injections | – nonsteroidal anti-inflammatory drugs (NSAIDs) – disease-modifying antirheumatic drugs (DMARDs) – methotrexate pills – corticosteroid injections, in some cases |
| Outlook | – lifelong condition – remission is possible with treatment | – remission occurs in | – can worsen over time – reduced mobility and functionality |
| Complications | – physical discomfort – reduced quality of life – higher risk of cardiovascular problems – negative effect on mental health – adverse effects of treatment | – severe itching – secondary infections – effect on physical appearance | – reduced mobility – chronic pain – higher risk of metabolic syndrome, including obesity and type 2 diabetes – changes to the shape of fingers, toes, and joints |
The symptoms of both psoriasis and PsA happen when a problem with the immune system leads to inflammation. They appear to result from a combination of genetic and environmental factors.
In psoriasis, the reaction causes skin cells to grow too fast, promoting a buildup of skin cells on the surface. These cells appear as a scaly rash.
In PsA, inflammation affects the joints. Permanent damage can result without treatment.
Doctors do not yet know precisely what causes the symptoms, but they have identified some genetic features that appear to play a role. Both conditions often run in families.
However, a person can have a relevant genetic feature and never develop psoriatic disease unless an event or condition activates it.
Psoriasis
Possible triggers for psoriasis
- stress
- an injury to the skin, such as sunburn
- an infection, such as strep throat
- the use of certain medications
- cold weather
- high alcohol consumption
- smoking
- obesity
Learn more about triggers for psoriasis here.
Psoriatic arthritis
- trauma, such as an injury
- high alcohol consumption
- high body mass index (BMI)
- an infection, including infectious diarrhea
- psoriasis that affects a large proportion of the skin
- heavy lifting
- stress
Risk factors can trigger initial symptoms of psoriasis or PsA, and they can also cause flares. Flares are cycles during which symptoms become worse. Triggers vary between individuals and may change over time.
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Psoriasis and PsA symptoms often come and go in cycles. They may get worse during a flare and then improve. Symptoms may also move around, affecting different areas of the body at different times.
Plaque and other types of psoriasis
There are several types of psoriasis, each with its own type of rash or set of skin changes.
Here are five of them:
- Plaque psoriasis: This is the most common type, affecting up to 8 in 10 people with psoriasis. It causes raised patches with a silvery white covering known as plaques. It often affects the scalp, elbows, knees, lower back, and nails. On pale skin, the lesions are red or pink. On darker skin, they may be violet or purple.
- Guttate psoriasis: This is the second most common type and occurs in about 8 in 100 people with psoriasis. It causes small red dots or bumps on the skin. It often occurs in children after a streptococcal infection.
- Inverse psoriasis: This causes a smooth, shiny rash in areas where the skin naturally folds, such as the groin and armpit. It affects around a quarter of people living with psoriasis. On darker skin, the lesions may be purple or darker than the surrounding skin. On pale skin, they will be red.
- Pustular psoriasis: This causes red blisters with white pus, often on the hands and feet. The blisters are not contagious or infected. Around 3 in 100 people living with psoriasis have pustular psoriasis.
- Erythrodermic psoriasis: This is a rare severe type of psoriasis. It causes a red, fiery rash over at least
90% of the body. It can affect people who have plaque psoriasis that is difficult to manage. It affects around 2 in 100 people with psoriasis. Erythrodermic psoriasis is a medical emergency and needs urgent attention.
Psoriasis can look different depending on a person’s skin tone. Areas that are red on pale skin may appear gray or purple on darker skin. People with darker skin are also more likely to have psoriasis without a diagnosis.
Erythrodermic and pustular psoriasis are more severe forms of psoriasis than plaque psoriasis. One study found that Americans of Asian or Hispanic and Latino heritage were more likely to have erythrodermic and pustular psoriasis than white people.
The authors concluded that genetics might play a role. However, these groups were also more likely to have severe skin psoriasis, possibly due to difficulty accessing healthcare.
What does psoriasis look like on darker skin?
Psoriatic arthritis
A person with PsA may experience:
- Joint pain: There may be pain, stiffness, and swelling in one or more joints, often of the fingers.
- Dactylitis: This occurs in 4 in 10 people with PsA and causes one or more fingers or toes to appear swollen or sausage-shaped.
- Enthesitis: Inflammation affects the tendons or ligaments where they join the bones, causing pain and tenderness. It is present in around half of cases.
- Spondylitis: Also known as axial PsA, this causes back and neck pain and stiffness. It is present in 7–32% of people with PsA.
Other possible symptoms of PsA include fatigue, stiffness in the morning, and reduced range of motion in the joints.
Dactylitis and enthesitis are key signs that can help doctors distinguish PsA from other types of arthritis.
Having severe psoriasis does not necessarily mean a person with PsA will have severe symptoms.
What is the link between dactylitis and PsA?
Psoriatic arthritis and psoriasis
Some symptoms can occur with both PsA and psoriasis
Nail psoriasis causes nails to crumble, become pitted or ridged, or separate from the nail bed. It affects
Uveitis is an eye inflammation that leads to redness and soreness, often
A doctor will speak with a person about their symptoms and carry out some tests to diagnose psoriasis or PsA.
Psoriasis
To diagnose psoriasis, a
- ask the person about their symptoms and family history
- examine the symptoms
- take a skin sample (biopsy) to confirm psoriasis
Psoriatic arthritis
The doctor will
- ask about symptoms
- ask about any history of psoriatic disease in the person or their family
- do a physical examination, including checking for dactylitis and enthesitis
- recommend imaging tests, such as an X-ray, MRI, or ultrasound scan
- do blood tests to rule out other forms of arthritis or causes of joint pain
For both PsA and psoriasis, the doctor may also screen for conditions that commonly occur with psoriatic diseases, such as obesity and other aspects of metabolic disorder.
How do racial differences affect the diagnosis and treatment of psoriasis?
A doctor can help a person choose medications and treatments for psoriatic disease. The options
Psoriasis
Treatments for psoriasis include:
- topical lotions, creams, and ointments, which may contain salicylic acid, coal tar, and vitamin D analogs
- moisturizers and emollients to hydrate and soften the skin
- corticosteroid creams to reduce inflammation
- phototherapy or light therapy
- topical or oral retinoids
- DMARDs, such as methotrexate
- biologic drugs, depending on the severity of symptoms
What are some oral medications for psoriasis?
Psoriatic arthritis
Treatment options for PsA
- NSAIDs to relieve mild pain
- occasional corticosteroid injections to relieve inflammation and swelling in joints
- DMARDs, such as methotrexate
- biologic drugs
- surgery to repair or replace damaged joints, in some cases
It is not always possible to prevent psoriasis or PsA, but some measures may help reduce the risk of flares or more severe symptoms.
Here are some tips. A person can:
- maintain a moderate weight
- take steps to avoid injuries and infections
- find ways to manage stress and anxiety
- speak with a doctor if any medications appear to make symptoms worse
- avoid smoking
- limit alcohol consumption
- follow an anti-inflammatory diet or a varied diet that contains plenty of fruits and vegetables
- exercise regularly
- follow a doctor’s recommendations and the treatment plan
People with skin psoriasis should also:
- cover the skin and hydrate well in cold weather
- avoid sun exposure and use air conditioning in warm or sunny weather
- bathe or shower in warm water, not hot water
Here are some questions people often ask about psoriasis and PsA.
Are psoriatic arthritis and psoriasis the same?
Both are psoriatic diseases, and a person who has psoriatic arthritis will often have psoriasis, but they are not the same disease. PsA affects the joints, but psoriasis causes skin lesions.
Which comes first, psoriasis or psoriatic arthritis?
In
What are the early signs of psoriatic arthritis?
People who develop PsA may already have nail psoriasis and skin symptoms. Early signs of joint involvement include swelling in the fingers, toes, or both, known as dactylitis. There may also be pain and tenderness where the tendons and ligaments meet a joint, known as enthesitis.
Psoriasis and psoriatic arthritis are both types of psoriatic disease. They are immune-mediated, and symptoms occur because of inflammation. They are different diseases but have a number of factors in common.
Psoriasis causes skin symptoms, but PsA causes pain and stiffness in one or more joints. However, people with PsA often have psoriasis, too.
People with either condition can have uveitis, an eye infection, or nail psoriasis. People with both nail psoriasis and skin symptoms may have a higher risk of developing PsA.
Treatment is available for both conditions. Some therapies are the same for both, while others are specific to the disease. PsA and psoriasis are lifelong conditions, but treatment can help move them into remission, when symptoms improve or go away for a while.