Why Does Psoriasis Show Up on Knees?

Knees and elbows, known as extensor surfaces, are common spots for psoriasis

Medically reviewed by William Truswell, MD

Psoriasis on knees and elbows is very common. In psoriasis, an immune system overreaction leads to inflamed, itchy skin covered in plaques or scales.

Healthcare providers aren’t sure why it appears more often on extensor surfaces, the skin covering a joint. However, they do know that these areas, including the knees and elbows, are more likely to have psoriasis than other areas of skin.

This article will give information about psoriasis on the knees and psoriasis on the elbows. It will cover how to treat dry elbows and knees and how to cope with psoriasis.

Psoriasis on Knees: What It Looks Like

The most common symptoms of psoriasis are inflamed and red areas of skin. Plaque psoriasis is the most common type, making up about 90% of psoriasis cases. Most cases of psoriasis on the knees are plaque psoriasis. In addition to the red flakes, you may notice a white or silver coating around the plaques on your kneecaps.

People with darker skin are less likely to notice red patches from psoriasis. If you have darker skin, you might notice hyperpigmented (darker) or purple-tinged areas instead.

Related: Psoriasis on Black Skin

Psoriasis Behind the Knee

Although rare, people with significant skinfolds behind the knee may develop inverse psoriasis in that area. Inverse psoriasis has raw-looking, smooth patches of painful skin, usually without scales. This type of psoriasis is uncommon and is most often seen in the armpits, genitals, and cleft of the buttocks.

Are Dry Elbows a Sign of Psoriasis?

The elbows are another common site of psoriasis. However, psoriasis isn’t necessarily the cause of dry elbows. As extensor surfaces, elbows, like knees, are often exposed and prone to bumps or scrapes. Over time, injuries can lead to skin thickening or dry skin.

Still, if you’re worried about your elbows or think you may have psoriasis, speak with a dermatologist.

Other Places Psoriasis Could Be

Psoriasis can appear on any part of the body. However, it’s more common in certain areas than others. In addition to the knees and elbows, plaque psoriasis is common on the scalp and lower back.

Plaque psoriasis and other types of psoriasis can also appear on the:

• Face

• Palms

• Soles of the feet

• Fingernails and toenails

• Mouth

Causes of Psoriasis Flares on Kneecaps

Psoriasis is an autoimmune skin condition in which the immune system, which normally protects your body from harm, reacts abnormally and causes skin cells to divide more rapidly. This leads to raised, inflamed patches that are scaly, dry, and itchy. The cause is believed to be an interplay of genetic predisposition and environmental factors. It is not contagious.

Like other autoimmune conditions, psoriasis is characterized by flares, which are periods of more intense symptoms. When a flare calms down, you may experience remission, when there are few or no symptoms. 

The causes of psoriasis flares can include everything from stress to weather changes to the clothing or soap that come into contact with your skin.

Healthcare providers aren’t sure why the kneecaps are more prone to psoriasis than some other body parts. One theory is that the skin here is under a lot of strain, whether from bending and moving, rubbing against clothing, being scraped, or other causes. These activities may make kneecaps prone to psoriasis symptoms.

The best way to identify the cause of psoriasis flares on your kneecaps is by keeping a symptoms journal. Taking notes can help you identify what contributes to your symptoms so you can limit future exposure to your triggers.

Associated Knee Complications

In addition to symptoms on the kneecaps, psoriasis can lead to pain, swelling, and stiffness in the knees. These are symptoms of a condition known as psoriatic arthritis, an autoimmune form of arthritis often with symptomos of psoriasis. Up to 40% of people with psoriasis will develop psoriatic arthritis.

This condition can make daily movements like walking or climbing stairs painful. Symptoms, especially stiffness, are often worse in the morning.

If you have symptoms of psoriatic arthritis in your knees, see a rheumatologist. These doctors specialize in treating inflammatory and autoimmune diseases and will be able to provide the care you need.

How Psoriasis on the Knees Is Diagnosed

A dermatologist is the best healthcare provider to diagnose psoriasis. Before giving you a diagnosis, they’ll examine you and discuss your symptoms. They’ll also take steps to rule out other skin conditions like eczema, which can be confused for psoriasis.

Treatment for Psoriasis on the Knees

Although there’s no cure for psoriasis, there are many treatment options. A dermatologist can help you develop a treatment plan for psoriasis on your knees. This might include topical creams, oral medications, light therapy, and biologics (which are injected or infused).

Topical treatments (applied to the affected skin) include corticosteroids, Vtama (tapinarof 1%) cream, and Zoryve (roflumilast) cream. You might also use preparations that contain coal tar, tazarotene, or salicylic acid.

Phototherapy uses ultraviolet (UV) light to slow skin cell growth, which can improve inflammation and itchiness. It can be delivered in various ways.

Oral medications include:

• Methotrexate (may also be injected) or cyclosporine to calm the immune response

• Otezla (apremilast) to prevent inflammation

• Soriatane (acitretin)

• Dovonex (calcipotriene)

In addition, there are home remedies and lifestyle changes that can help keep psoriasis symptoms at bay. Avoiding triggers, moisturizing regularly, and wearing clothing that does not worsen your symptoms can be helpful.

Emollients (substances that increase the skin's softness, smoothness, and elasticity) can help prevent skin cracks, relieve irritation, and clear scales. They help the skin retain moisture and maintain its barrier. There are many choices, including Vaseline or Aquaphor (petrolatum), oils, and sorbolene cream.

Emotional Impact of Psoriasis

Psoriasis on the knees can be very visible. It can also impact the types of clothing you can (or can’t) wear. That can compound the emotional and mental toll of psoriasis. Therapy can be a powerful tool to help people living with a psoriasis diagnosis cope.

Summary

It’s common to have psoriasis on the knees. Knees and elbows, known as extensor surfaces, are frequent locations for psoriasis flares, although the condition can appear anywhere.

In addition to skin symptoms like itchiness and redness, people with psoriasis can develop psoriatic arthritis, which leads to stiffness, pain, and inflammation in joints, including the knee.

A dermatologist and rheumatologist can help you develop a multifaceted treatment plan to address psoriasis on the knees.

Read the original article on Verywell Health.