Psoriasis: Symptoms, Causes & Treatment

Psoriasis is a chronic inflammatory autoimmune skin condition that causes red, scaly patches, itching, burning, and dry or cracked skin. It most commonly affects the elbows, knees, scalp, hands, and feet, although it can develop anywhere on the body.

The exact cause of psoriasis is unknown, but it is linked to genetic and environmental factors that can trigger or worsen flare-ups, including stress, infections, and certain medications. Psoriasis is not contagious, and symptoms may vary depending on the type of psoriasis.

Psoriasis is diagnosed by a dermatologist based on a physical examination and, in some cases, a skin biopsy. Treatment aims to control symptoms and prevent flare-ups with medications, phototherapy, and healthy lifestyle habits, although there is currently no cure.

Psoriasis symptoms

The main symptoms of psoriasis include:

• Red patches or plaques on the skin

• Flaking or scaling in the affected area, similar to dandruff

• Itching or a burning sensation

• Dry skin in the affected area

• Cracks in the plaques that may bleed

Psoriasis symptoms can appear on the arms, elbows, hands, legs, knees, genitals, scalp, abdomen, tailbone, or lower back. The symptoms vary depending on the type of psoriasis.

It is important to consult a dermatologist to identify the type of psoriasis and determine the most appropriate treatment.

How long do symptoms last?

The duration of psoriasis symptoms varies because the condition follows a cyclical pattern. Symptoms may last for several weeks or months and then disappear for a period of time without treatment.

However, the symptoms can return, especially during periods of increased stress.

Confirming a diagnosis

A dermatologist usually diagnoses psoriasis by reviewing the person’s symptoms and medical history and examining the skin, nails, and scalp.

In most cases, no laboratory tests are needed. According to the American Academy of Dermatology, a dermatologist may perform a skin biopsy when the diagnosis needs to be confirmed.

Blood tests may be ordered in certain cases to evaluate related health conditions, investigate possible psoriatic arthritis, or determine whether a systemic or biologic treatment can be used safely.

What causes psoriasis?

The exact cause of psoriasis is unknown. However, it is considered an autoimmune disease mediated by T lymphocytes and influenced by genetic and environmental factors.

Factors that may increase the risk of developing psoriasis include:

• Skin injuries

• Sunburn or insect bites

• Cuts, scratches, or skin damage caused by chemicals or radiation

• Viral or bacterial infections

• Smoking or excessive alcohol use

• Emotional stress

• Certain medications, especially antimalarial drugs, lithium, or beta-blockers

Psoriasis also has a strong genetic component, as more than 50% of affected people have other cases of psoriasis in their family.

Types of psoriasis

The main types of psoriasis are:

1. Plaque psoriasis

Plaque psoriasis, also known as psoriasis vulgaris, is the most common form of the condition. It causes red plaques covered with white or silvery scales that can range from a few millimeters to several centimeters in size.

This type of psoriasis usually appears on the arms, legs, scalp, and lower back. However, it can also affect the nails.

2. Guttate psoriasis

Guttate psoriasis is more common in children, adolescents, and young adults. It causes small, drop-shaped spots on the skin.

The spots are usually less than 1 cm, or approximately 0.4 inches, in size and tend to appear on the trunk, underarms, and groin. They often develop after a Streptococcus respiratory infection.

3. Pustular psoriasis

Pustular psoriasis causes small pus-filled blisters to appear along with patches on the skin.

The blisters may develop in one specific area or spread throughout the body.

When pustular psoriasis becomes widespread, the person may also have a fever of 102.2°F to 104°F, or 39°C to 40°C, for several days.

4. Inverse psoriasis

Inverse psoriasis causes patches to appear mainly in moist skin folds, such as the underarms, groin, area under the breasts, navel, or scalp.

Because these patches develop in moist areas, they usually do not have significant scaling.

5. Nail psoriasis

Nail psoriasis occurs when the condition primarily affects the fingernails or toenails. It can cause nail pitting, discoloration, and weak, brittle nails.

In many cases, nail psoriasis appears before psoriasis develops on the skin. It may be the only symptom for several years.

6. Scalp psoriasis

Scalp psoriasis causes the typical symptoms of psoriasis on the scalp. It may also cause hair loss in the affected area.

Symptoms can spread from the scalp to the ears, back of the head, neck, or face, especially the forehead. When the face is affected, the condition is commonly referred to as facial psoriasis.

7. Genital psoriasis

Genital psoriasis may affect the pubic area, thighs, buttocks, anus, penis, or vulva.

This type of psoriasis can cause severe itching or irritation in the genital area. Symptoms may worsen with sweating or when wearing tight, warm clothing.

8. Palmoplantar psoriasis

Palmoplantar psoriasis affects the palms of the hands, the soles of the feet, or both. It can cause red, dry patches, itching, burning, pain, and cracks in the skin.

When the condition affects the feet, it is commonly referred to as foot psoriasis. When it affects the hands, it is known as hand psoriasis.

Palmoplantar psoriasis can make everyday activities more difficult, such as walking, wearing shoes, or holding objects.

9. Psoriatic arthritis

Psoriatic arthritis is a chronic inflammatory form of arthritis that develops in some people with psoriasis. It affects the joints and commonly causes pain in the fingers or toes.

However, it can also affect the hips, spine, or knees. Psoriatic arthritis may develop together with skin psoriasis or nail psoriasis.

10. Erythrodermic psoriasis

Erythrodermic psoriasis is a severe form of psoriasis in which symptoms affect approximately 90% of the body’s surface. It usually causes intense itching, pain, or swelling.

This condition can develop as a severe flare-up of plaque psoriasis. It may occur after corticosteroid treatment is stopped suddenly.

Is psoriasis contagious?

According to the National Psoriasis Foundation, psoriasis is not contagious and cannot be passed from one person to another through physical contact. However, some infections may trigger psoriasis flare-ups in people who have the condition.

Psoriasis is an autoimmune condition, meaning the immune system mistakenly attacks skin cells as though they were foreign to the body, resulting in psoriasis symptoms.

Psoriasis treatment

Psoriasis treatment should be managed by a dermatologist. The goal of treatment is to relieve symptoms, prevent flare-ups, and improve quality of life.

The main treatments a doctor may recommend include:

1. Psoriasis medication

Medications used to treat psoriasis mainly include corticosteroids, immunosuppressants, and biologic agents. Examples include hydrocortisone, tacrolimus, methotrexate, cyclosporine, risankizumab, and adalimumab.

Depending on the medication, these treatments may be available as tablets, injections, creams, or ointments. They help control symptoms, reduce immune system activity, and decrease skin inflammation.

Some home remedies may also be used with a doctor’s approval to help control symptoms without interfering with medical treatment. Watercress is cited as one example because it is believed to help the body eliminate substances that may trigger psoriasis flare-ups or worsen symptoms.

2. Phototherapy

Phototherapy involves exposing the skin to UVB light. It is often used together with medications and topical treatments to increase their anti-inflammatory and antiproliferative effects.

3. Diet

A psoriasis diet may be used to complement the treatment recommended by a doctor. It involves eating anti-inflammatory foods that may help reduce skin inflammation, decrease the severity of lesions, and reduce the frequency of flare-ups.

Can psoriasis be cured?

Psoriasis has no cure, as no treatment can completely eliminate the condition. However, symptoms can be effectively managed with therapies prescribed by a dermatologist, which may also help prevent new flare-ups.