Psoriasis is a long-lasting condition in which the immune system becomes overactive. The result is thick, red, raised patches, often covered with silvery-white scale, that may itch or burn. It affects nearly 7.5 million people in the United States, men and women equally. It is seen mainly in adults, most often between 45 and 64, though children get it too. It is not contagious.
Psoriasis cycles between flares and calmer periods. There is no cure yet, which is why the goal of treatment is control rather than a one-time fix.
What it looks like and what sets it off
About 80 to 90% of people with psoriasis have the plaque type: raised patches, usually on the scalp, elbows, knees and lower back. They often itch, and scratching can make them thicker. Other types look different. Guttate psoriasis shows as many small, scaly spots that appear suddenly, often after strep throat. Inverse psoriasis forms smooth, red, raw-looking patches where skin touches skin. Pustular psoriasis brings pus-filled bumps, usually on the hands and feet.
Psoriasis can look different on darker skin. Instead of red or pink, the patches often look violet or dark brown, and the scale can look gray, which can make psoriasis harder to recognize.
About half of people with plaque psoriasis get nail changes at some point: tiny pits, white, yellow or brown discoloration, crumbling, or nails lifting off the nail bed.
Common triggers include stress, skin injuries, infections such as strep, smoking, heavy or frequent drinking, dry cold weather, sunburn, and some medicines. A cut, scrape, sunburn or bug bite can set off a flare near or in the same spot, and tattoos, piercings and shaving nicks are on the trigger list for the same reason. Excess weight makes symptoms worse.
When to see a dermatologist
- Dry, thick, raised patches that do not clear up.
- Psoriasis that is getting worse, or not improving with the treatment you are using.
- A swollen, tender finger or toe joint, heel pain, or stiffness in the morning that fades as the day goes on. These are early signs of psoriatic arthritis, which develops in about 1 in 3 people with psoriasis and can cause lasting joint damage if left untreated.
Skin that looks burnt over most of the body, with chills, fever or a racing pulse, can be erythrodermic psoriasis. Widespread pus-filled bumps with fever can be generalized pustular psoriasis. Both are rare, and both need emergency care.
What happens at the visit
A dermatologist examines the skin, scalp and nails and asks about itching or burning, recent illness or stress, the medicines you take, relatives with psoriasis, and any joint pain. When the diagnosis is unclear, they may take a small skin sample to look at under a microscope, which rules out conditions that look similar. Bring a list of everything you take, since some medicines can trigger flares.
How dermatologists treat it
Treatment depends on the type of psoriasis, how severe it is, where it is on the body, and the side effects a person can accept.
- Topical medicines. Creams, ointments, and medicated shampoos for the scalp, often including a corticosteroid, along with vitamin D-based medicines, retinoids and coal tar. Newer non-steroid creams include roflumilast (Zoryve), which calms inflammation by blocking an enzyme called PDE4, and tapinarof (Vtama in the United States, Nduvra in Canada), which works on the same skin pathway as coal tar. Topical JAK inhibitor creams are also used for psoriasis in some cases. These are the usual start for mild to moderate psoriasis.
- Light therapy. Controlled ultraviolet light given in the office, or with a prescribed home unit, usually when large areas of skin are involved or symptoms have not improved with creams.
- Systemic medicines. Pills and other medicines that work through the whole body, used for more severe psoriasis.
- Biologics. Injected medicines that block specific immune signals, which helps decrease or stop the inflammation.
If a medicine prescribed for something else seems to be causing flares, the American Academy of Dermatology advises raising it with the doctor who prescribed it rather than changing it alone.
Living with it day to day
Short, lukewarm baths or showers, mild soap, and a heavy moisturizer applied while the skin is still damp all help. So does a humidifier in dry, cold months. Keeping a healthy weight, not smoking, and limiting alcohol are part of the standard self-care advice, since obesity worsens symptoms and some studies link alcohol to worse psoriasis. A little sunlight can help some people, but sunburn triggers flares, so ask the dermatologist how much is right. Psoriasis can weigh on mood, and counseling is a normal part of care.
How to choose a dermatologist
Ask how much of the practice is psoriasis care and whether they offer light therapy on site. Ask how they check for psoriatic arthritis and whether they work with a rheumatologist. Ask what comes next if creams do not work. Check whether your insurance needs a referral, and whether newer medicines need prior approval from your plan.
The city list below shows dermatologists who name psoriasis on their own websites.