The majority of people with psoriatic arthritis first experience skin symptoms. One of the most common is a rash with thick, discolored skin covered with flaky, lighter-colored patches.
Psoriatic arthritis (PsA) is a form of arthritis that affects about one-third of people with psoriasis, according to the Arthritis Foundation. PsA is a chronic autoimmune disease that can, over time, lead to joint inflammation, stiffness, and pain.
The National Psoriasis Foundation reports that about 85% of people who have PsA will experience skin symptoms long before their joints are affected. One of the most common symptoms of PsA is a rash: thick red or discolored skin covered with flaky white patches.
If you develop symptoms of PsA, it’s important that you seek treatment as soon as possible. This can reduce your risk of joint damage associated with the condition.
Keep reading to learn how to identify a PsA rash, where it may appear, and how to treat it.
The rash seen with PsA is a psoriasis rash. The most common type features raised patches of discolored skin covered with silvery-white scales, called plaques.
Plaques may itch, burn, or hurt. If you have plaques, it’s important not to scratch them. Scratching may cause the plaque to thicken or open the skin to infection.
The rash may come and go. You may have extended periods when you’re rash-free. Certain conditions, such as infections, stress, and injuries, may trigger rash outbreaks.
If you have psoriasis and notice a change in your usual rash pattern or location, talk with your doctor.
A PsA rash typically develops on your:
- elbows
- knees
- scalp
- lower back
- genitals
- around the belly button
- between the buttocks
However, the rash can appear anywhere on your body, including your palms and soles.
Nail psoriasis is commonly associated with PsA, too. It can affect both the fingernails and toenails.
Nail psoriasis may cause:
- pitting
- discoloration
- onycholysis (nails that detach from the nail bed)
- tenderness
Your treatment plan will vary based on the type of psoriasis you have and the severity of your rash symptoms. With PsA, your treatment plan will also include drugs to help manage arthritis symptoms.
For the rash, your doctor may prescribe:
- creams and ointments to soothe your skin
- oral drugs to reduce skin cell production
- light therapy to reduce inflammation
The goal of rash treatment is to reduce plaque formation by stopping the skin cells from growing too quickly and by smoothing your skin.
Topical remedies
Topical medications can help relieve itchiness, dryness, and inflammation caused by a PsA rash.
Depending on the medication, this may be achieved with a:
- cream
- gel
- lotion
- shampoo
- spray
- ointment
These medications are available in both over-the-counter (OTC) and prescription formulas.
Common OTC remedies typically include salicylic acid and coal tar. Prescription treatments generally contain corticosteroids or vitamin derivatives.
Common prescription topicals include:
- calcitriol, a naturally occurring form of vitamin D3
- calcipotriene, a lab-made form of vitamin D3
- calcipotriene combined with the corticosteroid betamethasone dipropionate
- tazarotene, a derivative of vitamin A
- anthralin, a lab-made form of the naturally occurring substance chrysarobin
- tapinarof, a nonsteroidal topical cream (an aryl hydrocarbon receptor antagonist)
- roflumilast, an enzyme that affects anti- and pro-inflammatory production
Your treatment plan may involve a combination of OTC and prescription medications. You and your doctor may have to experiment to find what combinations work best for you.
Some medications, like corticosteroids, may have side effects when taken long term. Talk with your doctor about the potential benefits and risks associated with each option.
OTC moisturizers can help calm your skin and counter the itching, but moisturizers alone usually will not heal the plaques.
Oral or injected drugs
A variety of drugs that target skin cell production or your immune system can help a PsA rash. These include:
Corticosteroids
These medications mimic cortisol, a naturally occurring anti-inflammatory hormone produced by your body. These drugs are normally taken by mouth and can help reduce inflammation. Injected forms can provide temporary inflammation relief.
Long-term use can result in facial swelling and weight gain. It may also increase your risk of osteoporosis.
Disease-modifying antirheumatic drugs (DMARDs)
These medications suppress the chemicals in your body that cause inflammation. This can help reduce and prevent joint damage. DMARDs are typically taken by mouth but can also be injected.
Biologics
These medications can prevent inflammation on a cellular level. Biologics are typically injected. The main types of biologics are:
- anti-tumor necrosis factor-alpha drugs
- abatacept
- ustekinumab
Each blocks different proteins within the body.
Your risk for infection may increase while taking biologics since they work by suppressing your immune system.
Light therapy
Natural or artificial ultraviolet (UV) in controlled amounts can be used to reduce psoriasis rash.
Common approaches include:
UVB light machine
Exposing your rash to UVB radiation produced by a light machine for small amounts of time a few times a week can help reduce inflammation. Dermatologists often have UVB machines for home use. You can also buy them commercially to use at home.
UVA light machine
This approach uses a light machine that produces UVA radiation. When combined with psoralen, a drug that makes your skin more light sensitive, this method can improve severe psoriasis. This is also known as photochemotherapy.
Excimer laser
An excimer laser concentrates more powerful UVB radiation on psoriasis spots. It’s a more targeted method to manage the rash. This is used in a doctor’s office and usually requires fewer sessions than other UV treatments.
Talk with your doctor about whether home or in-office sessions are right for you.
Home remedies
Certain lifestyle strategies can also help manage itching and inflammation.
Tips and tricks
- Keep your skin moisturized, especially when the air is dry. You may need to apply a moisturizer a few times a day.
- Take warm baths to calm itchy and inflamed skin. Add Epsom salts, colloidal oatmeal, or oils to soak in. Use only mild soaps.
- Avoid things that seem to trigger outbreaks, such as stress, alcohol, smoking, or certain fragrances.
- Prioritize a nutrient-dense, balanced diet and get regular exercise to boost your overall well-being.
Psoriasis is a chronic (long-term) condition with no known cure. It affects every person differently. How fast your rash clears depends on its severity and the effectiveness of your treatment plan.
It may take a while for you and your doctor to find a combination of treatments that manage your skin symptoms. Rashes usually clear up and you’ll have a period of remission, but they can flare up again.
If you learn to recognize and avoid what triggers flare-ups, you may be able to reduce the frequency of them.
Although a rash is a common indicator of PsA, you can develop PsA without having a rash.
In these situations, it’s important to know the other symptoms of PsA.
Although a rash is commonly associated with PsA, it’s not the only symptom.
Other symptoms include:
- tiredness
- morning stiffness and low back pain
- swelling, pain, or tenderness in joints
- tendon or ligament pain
- reduced range of motion in joints
- nail changes, such as pitting and cracking
- dactylitis, or swollen fingers and toes that look like sausages
- eye problems, including redness, irritation, and conjunctivitis
PsA symptoms and their severity vary from person to person. Many symptoms mimic those of other diseases, such as osteoarthritis, rheumatoid arthritis, and gout.
If you’re experiencing PsA symptoms, be sure to talk with a doctor. Getting a diagnosis as soon as possible can help improve your quality of life and reduce your risk of long-term complications.