Psoriasis

Psoriasis can present itself in many forms, so it’s impossible to know which type of psoriasis you’re most likely to develop until you receive a diagnosis from a board-certified dermatologist. However, knowing what each type looks and feels like, as well as what may influence its development can help you identify what’s going on with your skin.

Plaque psoriasis

About 80% to 90% of people with psoriasis have plaque psoriasis, making it by far the most common form you can get, according to the American Academy of Dermatology Association (AAD). Skin plaques—thick, raised plaques of skin typically covered in white, silvery, or grayish scale—are the hallmark sign. Depending on your skin tone, the underlying lesion may be pink, red, salmon-colored, violet, or simply darkened in color, according to the Skin of Color Society. Plaques can be any size and appear nearly anywhere, but they’re most commonly found on your elbows, scalp, knees, and/or lower back.

Guttate psoriasis

Guttate psoriasis (meaning resembling a drop) presents as small, round, scaly bumps scattered across your torso, legs, and arms. However, it can also show up on your face, scalp, and ears.

It usually comes on suddenly and is triggered by an infection like strep throat, although the reason for this isn’t clear, according to the AAD. Not everyone will develop guttate psoriasis after having strep throat, but the theory is that those who do are genetically predisposed to it. It makes sense then that children and young adults, who are prone to picking up infections, are more likely to have this form of psoriasis. Sometimes guttate psoriasis clears up in a few weeks or months on its own without treatment; other times people have it for life or their guttate psoriasis clears up but they develop plaque psoriasis later on. In fact, about 40% of people with guttate psoriasis end up with plaque psoriasis.²

Inverse psoriasis

Inverse psoriasis, also known as intertriginous psoriasis or flexural psoriasis, appears as smooth, sharp, well-demarcated patches of inflamed skin. Unlike plaque psoriasis, these areas look very raw and have little to no silvery coating. They can feel very uncomfortable, sore, and even painful.

Inverse psoriasis usually shows up in skin folds or other areas of the body where skin touches or rubs against other skin, such as the armpits, below the breasts, genital area, or between the buttocks. While inverse psoriasis typically doesn’t cover large portions of the body, it can still have a big impact on a person’s quality of life due to the sensitive locations of the rash. Experts believe fungal or bacterial infections in these skin folds may be the most likely trigger of this type of psoriasis, but more research is needed.³

Pustular psoriasis

Pustular psoriasis causes pus-filled bumps, usually on your feet and hands, that make it nearly impossible to walk or hold on to things.

Very rarely, pustular psoriasis covers large areas of the body, which is referred to as generalized pustular psoriasis or von Zumbusch psoriasis when it happens. This type of flare happens very suddenly, and your skin may appear very inflamed and dry before the pus-filled bumps form, according to the AAD. These bumps can break open, dry out, and peel—all within two to three days. If this happens, then you should seek emergency medical attention to get treatment because the condition can lead to fatal complications.⁴

Erythrodermic psoriasis

This is extremely rare and occurs only in about 1% to 2.25% of people with psoriasis, according to a 2016 study published in Psoriasis. Generally, erythrodermic psoriasis happens in people who already have another type of psoriasis, which is either worsening or not improving with treatment. With erythrodermic psoriasis, you’ll develop a peeling rash on your entire body that makes your skin look as if it were burnt. This is a serious, life-threatening condition, so if you notice any of the symptoms—you may also develop chills, fever, muscle weakness, rapid pulse, and severely itchy skin—then it’s important to get medical attention as soon as you can.

Nail psoriasis

Psoriasis can manifest in the fingernails, usually in addition to skin lesions but sometimes on its own, says Dr. Helfrich. “It’s most commonly misdiagnosed as nail fungus,” she explains. You’ll have nail changes (which we’ll detail in a bit below) that can impact your ability to walk or use your hands. Nail changes can also be a sign of psoriatic arthritis, another autoimmune condition that people with psoriasis are prone to.

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Psoriasis symptoms can look and feel really different from person to person, depending on the type of psoriasis you have and the severity of your condition. It’s a common misconception that all forms of psoriasis are itchy or painful.

“Sometimes it is completely asymptomatic and sometimes it will itch, but it can vary quite a bit,” Dr. Helfrich says. “People can have a few very small plaques just on their elbows or knees, or they can have almost 100% of their body covered.”

The more common symptoms of plaque psoriasis include:

• Patches of thick raised skin lesions that become covered in dry and flaky scales
• Small scaling spots or visibly peeling and flaking skin
• Dry, cracked skin that may bleed, especially on the elbows and knees
• A flaky scalp
• Plaques that itch, burn, or feel sore

It’s important to note that plaques can take on different coloring in different skin tones. In people with fair skin, psoriasis tends to be red or pink with silvery-white scales; in medium-colored skin tones, it can look more salmon-colored with silvery-white scales; in dark skin tones, it can look violet or dark brown with gray scales, per the AAD. Because of this, psoriasis can be harder to see on brown or Black skin.

Symptoms of less common forms of psoriasis include:

• Guttate psoriasis causes clusters of small bumps and scales that are typically less than 1 centimeter in diameter.
• Inverse psoriasis causes a shiny, smooth, inflamed rash that has very little scaling. Generally, this appears in skin folds and feels very sore.
• Pustular psoriasis can cause dots and scaling in addition to the pus-filled bumps.
• Erythrodermic psoriasis causes an itchy, burnlike rash along with chills, fever, muscle weakness, and a fast pulse.
• Nails psoriasis can make your nails look white, yellow, or brown, in addition to making your nails feel really rough and crumbly, too. Other symptoms include tiny dents in the nails (called pitting) and separation of your nail from your nail bed.

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You can develop psoriasis symptoms for the first time or have a flare-up of symptoms after experiencing a particular trigger. Not everyone with psoriasis has the same trigger, but the AAD says the most common ones can include:

• Chronic stress, say, due to a chaotic work schedule or sudden loss of a loved one
• Infections, such as strep throat or bronchitis
• Taking certain medications, like lithium or high blood pressure medications
• Suddenly going off corticosteroid medications
• Smoking or being exposed to a lot of secondhand smoke
• Skin injuries, such as a cut, a scrape, a bug bite, or sunburn
• Dry, cold weather with low humidity

Figuring out your individual triggers will help you learn how to avoid them, so you can ultimately reduce psoriasis flares. Doctors, unfortunately, don’t have a good way of predicting what might set off symptoms for each person, Dr. Helfrich notes, so it’s important to take note of possible factors after your symptoms begin or start to become more prevalent again.

Keeping the most common triggers in mind, think about what kind of activities, behaviors, and environmental factors seem to be associated with your flares. Having a journal where you write down what you were doing, the weather, how you were feeling, and what you drank and ate on days your symptoms flared can help you identify your triggers.

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Most of the time, a board-certified dermatologist can recognize and diagnose psoriasis during an in-office exam, Dr. Helfrich says. They’ll take a close look at your skin, nails, and scalp for signs of psoriasis and ask you questions about your symptoms and family history. There are no specific diagnostic criteria or blood tests to determine if you have psoriasis.

If your dermatologist needs more help making a definitive diagnosis, they may perform a skin biopsy. During a biopsy, a small amount of skin is removed and then examined under a microscope to determine whether it is, indeed, psoriasis.

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The best psoriasis treatment for you will depend on a few things. “A key part of treatment is knowing what type of psoriasis you have,” Dr. Helfrich says. The subtype and how much of the body is covered in psoriasis are the two biggest factors that dictate the appropriate treatment. Beyond that, some treatments will work well for some people, and not so well for others, so it may take some trial and error to find the best psoriasis treatment for you.

The three main categories of psoriasis treatment are topical medications, phototherapy, and oral and injected medications. They’re typically prescribed in that order, depending on how severe the psoriasis is, according to the Mayo Clinic.

Topical medications

• Corticosteroids: These are an anti-inflammatory topical medication, meaning they help reduce redness and itchiness. You can find these in various strengths formulated as ointments, creams, lotions, gels, foams, sprays, and shampoos. Mild, over-the-counter corticosteroids can be used on sensitive areas, like your face or genitals, while stronger options may be used on hard-to-treat psoriasis that appears on tougher skin. Generally, corticosteroids are used for short periods of time because they can thin your skin, so it’s best to talk to your doctor about how to use topical steroids safely.⁵ (You’ll also want to avoid using these in really delicate areas, like on your eyelids.)
• Vitamin A: Also known as retinoids, derivatives of vitamin A are offered as creams and gels. They help regulate your skin cell growth, decrease scales, and reduce redness and swelling, according to the AAD.
• Vitamin D: Calcipotriene cream uses a synthetic form of vitamin D to help reduce redness and scaling.
• Calcineurin inhibitors: Available as immunosuppressive ointments and creams, these effectively reduce psoriasis plaques. They are safer for areas where your skin is thinner, like around your eyes, where other treatments may be too irritating.
• Salicylic acid: This beta-hydroxy acid is a gentle exfoliator that softens psoriasis patches, ultimately helping other medicines penetrate the skin more easily to work more effectively.
• Coal tar: This is an effective treatment normally found in shampoos for scalp psoriasis, but it’s not the most popular option because it doesn’t smell great and can make your hair dry.

Phototherapy

Phototherapy, or light therapy, is used to treat moderate to severe psoriasis. It’s exactly what it sounds like: exposing your skin to a controlled amount of light. It works by prompting certain immune cells, which are driving the inflammation process, away from the skin, Dr. Helfrich explains.

There are numerous types of phototherapy. Your doctor might recommend brief sunlight exposure every day, or they may recommend using artificial light. Within the latter, there are different types of light, such as narrowband or broadband UVB light and psoralen plus ultraviolet A (PUVA). If you’re interested in light therapy, talk to your doctor about which option is best for your specific condition. This type of treatment is offered in office, and you’ll likely need to schedule an appointment about two to three times a week for several weeks, the AAD says.

What’s more, all types of phototherapy have potential side effects, including skin redness, dryness, burning, and an increased risk of skin cancer. It’s important to work with a dermatologist who can prescribe the right treatment with the least amount of side effects.

Oral and injected medications

Systemic medications, either delivered orally or via injection, can be used to treat moderate to severe psoriasis when topical treatments don’t work well. For example:

• Steroids are injected directly into a skin lesion to help with redness, inflammation, and itchiness.
• Retinoid pills help slow your skin cell growth.
• Methotrexate, an oral medication, helps suppress inflammation and reduce skin cell build-up.
• Cyclosporine, another oral medication, suppresses inflammation and reduces skin cell build-up. It is prescribed for severe psoriasis.
• Biologics, which are offered as IV infusions or at-home injectables, target the part of the immune system that causes psoriasis.

Systemic medications tend to work well, but have the potential for more side effects, including an increased risk of infections, as many options suppress the immune system. Your doctor will help you weigh any potential risks and monitor you throughout treatment to ensure you’re getting the most benefit from your plan.

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Unfortunately, there isn’t a single diet that can help with psoriasis. (If only!) Some studies have explored various eating styles and how they potentially affect psoriasis symptoms, but there isn't any solid evidence to confirm what people with psoriasis should or shouldn’t eat to reduce flares. “The connection between diet and psoriasis is poorly explored, and we don’t have any definitive information,” Dr. Helfrich says.

However, triggers are very personalized, so if you find that you tend to flare around the same time you eat a certain food or category of food, it’s not a bad idea to talk to your doctor about that. It’s really important to discuss any major diet changes with your physician or a registered dietitian, so you don’t cut out essential nutrients, which can lead to unpleasant side effects like low energy or unintended weight loss.

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About 30% of people with psoriasis will also develop psoriatic arthritis (Ps.A.), a form of inflammatory arthritis that causes joint stiffness, swelling, and pain that can become quite debilitating if left untreated. Psoriatic arthritis is also caused by a wonky immune system reaction, according to the Mayo Clinic.

Most people with Ps.A. develop psoriasis first, but some people have joint problems first, joint problems and no skin involvement, or joint problems and nail psoriasis. If you have both conditions, they won’t necessarily get better or worse in tandem. “Sometimes the skin can improve, but you still have joint problems and vice versa,” Dr. Helfrich says.

Psoriatic arthritis can impact any joint in the body, but most commonly occurs in the spine and the joints in the hands and feet, wrists, ankles, and knees. According to the Mayo Clinic, it can also cause painful swelling in the fingers and toes, foot pain in areas where tendons and ligaments attach to bones (like the Achilles tendon and sole of the foot), and a condition called spondylitis, or inflammation of the joints between the vertebrae of the spine.

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Psoriasis and eczema are commonly confused for each other, Dr. Helfrich says. It makes sense because eczema is another condition that causes dry, itchy skin. It’s important to know the difference between psoriasis and eczema because the two conditions are treated very differently. 

Dr. Helfrich says there are some key differences between psoriasis and eczema:

• Only psoriasis is clearly defined as an autoimmune condition.
• Psoriasis plaques are often symmetric on both sides of your body (but not always).
• Eczema rashes tend to be flatter and not as raised as psoriasis lesions.
• Eczema is usually itchier, and psoriasis is usually more painful.
• Eczema is generally found on the insides of the knees and elbows, whereas psoriasis is really found anywhere on the skin, according to the AAD.
• Eczema in children may improve or go away completely with age; untreated psoriasis usually gets worse with time.
• Eczema is often improved with good skin care, and in some people, can be prevented by avoiding irritating chemicals, allergens, or stress.

However, the two can be similar in a few ways as well:

• Both psoriasis and eczema tend to go through periods of remission (when symptoms go away) and flares (when symptoms start back up again).
• Both are thought to be caused by a mix of genetics and environmental factors.
• Neither is contagious.
• Both eczema and psoriasis can be treated with topical corticosteroids and various forms of light therapy.

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There’s a very real connection between psoriasis and mental health. In fact, it can be a vicious cycle. Research shows that psoriasis can contribute to or worsen various mental health conditions, including depression, anxiety, and eating disorders, according to a 2016 paper published in the Journal of Clinical and Aesthetic Dermatology.⁶ In fact, up to 23% of people with psoriasis said they experienced anxiety compared with up to 11% among people without the condition, according to a review of studies published in Seminars in Cutaneous Medicine and Surgery.⁷ Consistently worrying about when you might have a flare and how it will affect your life can really get to you. “The impact of psoriasis on quality of life is huge,” Dr. Helfrich says.

Plus, psoriasis can be a very visible disease, which can understandably affect a person’s self-confidence. This can be isolating and make it hard to open up and connect with other people and build relationships, Dr. Helfrich says. The misconception that psoriasis is contagious can also make it hard for people with psoriasis to feel comfortable around strangers or people who don’t understand what the disease actually is.

Living with psoriasis can be challenging, but there are so many treatment options available to help control the condition, so you can still live a very full life with it. “We are so fortunate because the therapies that are available now are just so much better than when I started in dermatology 20 years ago,” Dr. Helfrich says.

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Sources:

1. International Journal of Molecular Sciences, The Genetic Basis of Psoriasis
2. StatPearls, Guttate Psoriasis
3. Clinical, Cosmetic and Investigational Dermatology, Inverse Psoriasis: From Diagnosis to Current Treatment Options
4. Postgraduate Medicine, A Brief Guide to Pustular Psoriasis for Primary Care Providers
5. Drug Safety, Topical Corticosteroid-Induced Skin Atrophy: A Comprehensive Review
6. Journal of Clinical and Aesthetic Dermatology, Psoriasis and Associated Psychiatric Disorders
7. Seminars in Cutaneous Medicine and Surgery, Common and Not-So-Common Comorbidities of Psoriasis