If you’re living with psoriasis, your immune system sends a message to the skin cells, telling them to make more cells than they should. For people without psoriasis, it ually takes up to a month for new skin cells to develop. With psoriasis, new skin cells mature every three to four days. As a result, these cells build up on the skin’s surface, forming thick, scaly patches.

A doctor usually diagnoses psoriasis by looking at your skin. It may be difficult to tell apart from other skin conditions like eczema, dandruff, or cutaneous lupus, and symptoms can vary depending on how severe it is and your skin tone.

How Is Psoriasis Diagnosed?

A dermatologist specializes in conditions of the hair, skin, and nails. They can help determine and confirm your condition if you experience itchy, dry, thick patches of skin and think you may have psoriasis. If you don’t already see a dermatologist, ask your primary care provider for a referral.

A dermatologist will diagnose psoriasis by inspecting the affected skin. They’ll look for symptoms of psoriasis, such as dry, scaly patches or thick, inflamed areas of skin. These patches, called plaques, may look red, brown, purple, or gray depending on your skin tone, and they’re often covered with white, silver, or grayish scales. Plaques are a symptom of plaque psoriasis, the most common type of psoriasis.

A dermatologist will examine your entire body, including your scalp and skin folds, as psoriasis commonly develops in those areas. They may ask about your family history of psoriasis and if you’re having other symptoms. For example, they may ask if you have nail problems, joint pain, or swelling and whether you’ve gone through any major life changes recently. These questions can help a dermatologist get a better picture of your health. If you have joint and nail symptoms, it may help confirm a psoriasis diagnosis. ​

When diagnosing psoriasis, your dermatologist will also diagnose the type of psoriasis you have, and they may talk about how severe your psoriasis is. Although plaque psoriasis is the most common, other types of psoriasis like inverse psoriasis, guttate psoriasis, and erythrodermic psoriasis are possible and appear with slightly different symptoms.

To measure psoriasis severity, dermatologists may use several tools, including the Psoriasis Area and Severity Index (PASI). With this tool, your dermatologist will rate how severe your psoriasis is based on the intensity of symptoms like discoloration, scaling, and thickness on a scale of zero to four (zero means none and four indicates very severe). Your dermatologist will also look at your head and neck, arms, midsection, and legs to determine the area or percentage of your body affected by psoriasis symptoms.

Depending on the type and severity of your psoriasis, your dermatologist will create a treatment plan. Mild psoriasis may only be treated with topicals like creams or ointments applied to the skin, whereas severe psoriasis may need biologic therapy. Biologic therapy, also called biologics or biologic drugs, is a treatment option for severe psoriasis. This type of treatment uses medications made from living organisms to target and control certain parts of the immune system that cause psoriasis to develop.

Punch Biopsy

In some cases, your dermatologist may want to rule out other skin conditions by performing a punch biopsy — a type of skin biopsy that’s most commonly used to diagnose psoriasis. The punch biopsy process should only take about five minutes, and your dermatologist can do it right in their office.

Before a punch biopsy, your doctor will clean the area of skin where you’re having symptoms. They may inject an anesthetic such as lidocaine or xylocaine to numb the skin. Then, they’ll use a device to puncture the skin and remove a small section (around 3 millimeters in diameter) of deeper layers of skin (the epidermis, dermis, and superficial fat). They may use one or two stitches to close the incision. ​

After the biopsy, your doctor may apply a bandage to the area from which they removed the skin sample. You may feel pain in the area after the anesthetic wears off.

Your doctor will then send the skin sample to an outpatient laboratory, where a pathologist will look at it using a microscope. A microscope helps doctors get a magnified, clearer view of the skin sample. It can show details about the skin and find skin diseases like psoriasis. Results from this type of biopsy are usually available within one week. Someone from your dermatologist’s office will either call you or post your results to your online patient portal.

Diagnosing Psoriatic Arthritis

If you have joint symptoms like joint pain, swelling, and stiffness in addition to psoriasis skin symptoms, your doctor might recommend testing for psoriatic arthritis (PsA). According to the National Psoriasis Foundation, around 30 percent of people with psoriasis have PsA.

Diagnosing PsA is a very different process from diagnosing a skin condition like psoriasis. Although no single test can confirm PsA, diagnosis may involve a physical examination, blood tests, or imaging procedures such as X-rays and CT or MRI scans.

Dermatologists often refer people with PsA to rheumatologists. A rheumatologist specializes in rheumatic diseases, which affect the joints, muscles, and bones. They have specialized knowledge in diagnosing and treating skin and joint symptoms related to PsA.

Scans help the doctor see if there’s any damage to your joints. Blood tests show how much inflammation is in your body and can help the specialist tell PsA apart from other conditions with similar symptoms, like rheumatoid arthritis. Having skin psoriasis can also make a PsA diagnosis more likely.

When someone has both PsA and psoriasis, it can change how the skin condition is treated. The treatment plan for psoriasis may be adjusted to help with joint pain and complications caused by PsA, so both the skin and joints can feel better.

What Is the Prognosis for Psoriasis?

Psoriasis is a chronic (ongoing) condition, although symptoms can come and go. During a flare, symptoms may show up in new areas or return to the same spots as before. They may also get better for a while during periods of remission.

There’s no cure for psoriasis, but there are effective treatments for many symptoms of psoriasis and psoriatic arthritis (together referred to as psoriatic disease). Psoriasis treatments can help keep your symptoms under control and help keep symptoms from showing up on new parts of your body.

If you have psoriasis, you may wonder whether it can affect your life expectancy. Psoriatic disease is rarely life-threatening. However, people with psoriatic disease have a higher risk of developing comorbidities (when you have more than one condition at a time). ​

Some comorbidities of psoriatic disease include:

• Inflammatory bowel disease
• Metabolic syndrome, which includes high blood pressure, high blood sugar, and/or high cholesterol
• Obesity
• High blood pressure
• Cardiovascular disease
• Cancer
• Diabetes
• Depression and anxiety
• Kidney disease
• Chronic obstructive pulmonary disease (COPD)

Metabolic syndrome, cardiovascular disease, cancer, kidney disease, and COPD, in particular, may affect your life expectancy. People with psoriasis and PsA must stay at a healthy weight, eat a nutritious diet, and get regular exercise to avoid developing these dangerous complications.

Treating your psoriasis can also help reduce your risk of these comorbidities. Regular treatment and follow-up for your psoriasis can help ensure that you’re being monitored for comorbidities. Regular blood pressure tests and blood work can help with recognizing comorbidities early, in addition to evaluating how your psoriasis treatment is working.

At What Age Does Psoriasis Start To Develop?

Psoriasis usually begins between ages 20 and 30 or between ages 50 and 60. However, psoriasis may develop in people of any age, even in young children and infants.

Because psoriasis is a chronic condition, you’ll want to work with a dermatologist to come up with a treatment plan for your symptoms. A health care professional can help review your treatment options and devise a plan to help you avoid common triggers and prevent flare-ups.

Find Your Team

MyPsoriasisTeam is the social network for people with psoriasis and psoriatic arthritis. On MyPsoriasisTeam, more than 133,000 members come together to ask questions, give advice, and share their stories with others who understand life with psoriasis.

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