Psoriasis is a chronic skin condition characterised by thick red patches with flaky silvery scales.

Psoriasis can be mistaken for dandruff when occurring on the scalp. Besides the scalp, psoriasis can affect any part of the skin, in particular the:

  • Knees

  • Elbows,

  • Hands,

  • Feet and

  • Lower back

In severe cases, the patches can be accompanied by painful joint swelling as well as joint disfigurement.

“Psoriasis patches can range from minor dandruff-like scaling to major eruptions covering large areas of skin,” says Associate Professor Pang Shiu Ming​, Senior Consultant from the Department of Dermatology at Singapore General Hospital (SGH), a member of the SingHealth​ group.

“In its severe form, psoriasis can be incapacitating, significantly affecting the patient’s quality of life. On rare occasions, very severe psoriasis can be life-threatening.”

In Singapore, an estimated 40,000 people suffer from the disease, according to the Psoriasis Association of Singapore. Psoriasis can affect men, women and children at any age, though it has been found to be more common between the ages of 15 to 45.

Mild and moderate psoriasis: How to manage

Mild and moderate psoriasis can be treated with:

  • Coal tar preparations (cream or shampoo)

  • Dithranol cream/ointment

  • Salicylic acid ointment

  • Corticosteroids cream/ointment

  • Vitamin D-type drugs such as calcipotriol and calcitriol cream/ointment

  • Fixed dose combination of corticosteroid and calcipotriol ointment/gel

  • Fixed dose combination of corticosteroid and salicylic acid ointment

Severe psoriasis: How to manage

More severe psoriasis may require treatment with phototherapy using ultraviolet light 2-3 times a week for a period of several weeks to several months. Phototherapy can produce side effects such as dryness and burns on the skin, and increases the risk of skin cancer.

Although phototherapy with ultraviolet light is used in the treatment of psoriasis, you are advised to take care to protect yourself from the damaging effects of the sun.

Persistent psoriasis may require oral and/or injectable medication as well as topical creams and ointments. Since oral and injectable medication presents risks to internal organs such as the kidney and liver as well as the immune system, this psoriasis treatment needs to be closely monitored.

“Psoriasis treatment involving oral and injectable medication and phototherapy can have side effects and the patient needs to be monitored with regular blood tests and follow-up visits,” says Assoc Prof Pang.​

Psoriasis: Common triggers to avoid

The following factors have been found to be triggers for the disease:
  • Skin or nail injury

  • Stress and anxiety

  • Infections such as a streptococcal (bacterial) throat infection

  • Certain medications such as antimalarial drugs or lithium

  • Exposure to cold

  • Overweight and obesity

  • Excessive alcohol consumption​

  • Smoking

“Smoking is a risk factor for psoriasis and has also been found to increase the severity of symptoms,” says A/Prof Pang.

Psoriasis symptoms

Most psoriasis patients have mild to moderate symptoms which are likely to wax and wane, appearing and disappearing in cycles. Psoriasis symptoms may flare up for a few weeks or months and then disappear for some time, even going into remission for some years. However, in most cases, the psoriasis symptoms do eventually recur.

A small number of patients suffer from the severe and persistent form of the skin disease.

Mild and moderate psoriasis symptoms include:

  • Dry cracked skin prone to bleeding

  • Burning, itchy skin

  • Raised red patches with silvery scales (called plaque)

Severe psoriasis symptoms include:

  • Inflamed and itchy patches covering large areas of skin

  • Stiff, swollen and painful joints

  • Disfigured joints, commonly fingers and toes

  • Thickened, discoloured nails which may separate from the nail beds

3 Types of psoriasis

  1. The most common type of psoriasis is plaque psoriasis, in which patches can occur anywhere on the body. Other common types include nail psoriasis and scalp psoriasis.

  2. Less common types include guttate psoriasis; localised pustular psoriasis; acropustulosis, palmoplantar pustulosis, palmoplantar psoriasis; and inverse or flexural psoriasis. Erythrodermic psoriasis and generalised pustular psoriasis (Von Zumbusch) are life-threatening forms of psoriasis.

  3. In psoriatic arthritis, the joints become painful and swollen.

Causes of psoriasis

Psoriasis is believed to be caused by a combination of genetic and environmental factors which affect the body’s immune system, causing its T-cells to attack healthy skin cells.

“A family history of psoriasis puts you at greater risk of getting the disease,” says Assoc Prof Pang.

The disease occurs when skin cells multiply rapidly, replacing old skin cells over 3-4 days instead of the normal 3-4 weeks. This rapid multiplication causes the cells to build up on the surface of the skin, forming thick patches.

Lead a healthy lifestyle to prevent relapse of psoriasis symptoms

Psoriasis is a chronic non-infectious skin condition which can’t be cured. However, symptoms, particularly in mild cases, can be controlled with topical creams, ointments and medication.​

“Avoiding triggers such as stress, and leading a healthy lifestyle, can also prevent a relapse of psoriasis symptoms,” advised Assoc Prof Pang.

Ref: L20

Check out our other articles on skin conditions:

Living with Psoriasis

Eczema: All You Need to Know

Stevens-Johnson Syndrome: A Potentially Deadly Skin Disease

Skin Cancer: Types, Symptoms, Treatment and Prevention Tips