Psoriasis

What is Psoriasis?

Dr Shreya Andric Psoriasis Dermatology Treatment Northern Sydney Derm.

Psoriasis is a chronic inflammatory skin condition which affects 2-4% of males and females. It can develop at any age, including in childhood, and affect any skin type, but occurs most frequently in Caucasians. A family history is common with about 30% of patients having family members with psoriasis. 

Psoriasis patients typically have red, scaly plaques with well-defined edges. These develop as a result of a sped-up skin production process. Usually, skin cells grow deep in the skin then slowly rise to the surface and eventually flake off. The typical life cycle of a skin cell is 28 days. In a person with psoriasis, this process may take just a few days and because of this, the skin cells don’t have a chance to fall off resulting in a build-up of scale.  These plaques can affect any part of the skin. The most frequently affected sites include the scalp, behind the ears, the nails, and the backs of the elbows and front of the knees. There are various types of psoriasis with the main one being chronic plaque psoriasis as well as guttate psoriasis which presents with multiple small plaques on the torso and limbs and typically occurs after a streptococcal throat infection. Psoriasis can also be classified by its location and affect certain areas of the body only including the scalp, the nails, the palms of the hands and soles of the feet, and the genital area.

Why does psoriasis happen?

Psoriasis is thought to be due to multiple different factors. Genetics play a big role in this condition and a person’s genetic profile (essentially the way their genes have been put together) influences their type of psoriasis as well as its response to treatment. Factors that aggravate psoriasis include:

  • Infections

  • Injuries

  • Sun exposure in 10% (most patients find sun exposure to be beneficial)

  • Obesity

  • Smoking

  • Excessive alcohol

  • Stressful life events

  • Medications

  • Stopping oral steroids

It is important to know that psoriasis is not contagious – you can’t “catch” psoriasis from someone.

Patients with psoriasis are also more likely to have other inflammatory conditions such as:

  • Psoriatic arthritis (can occur in up to 40% of people with early-onset chronic plaque psoriasis and presents with joint pain, stiffness and swelling especially of the fingers, toes, feet and lower back)

  • Inflammatory bowel disease including Crohn’s disease and ulcerative colitis

  • Uveitis (a type of inflammation of the eye)

  • Coeliac disease

  • Metabolic syndrome, which includes high blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol levels.

Psoriasis is usually diagnosed by its clinical appearance and features. Occasionally, a skin biopsy may be required.

How to manage Psoriasis

Mild psoriasis can be managed by a general practitioner. Patients with more severe disease may choose to see a dermatologist as we manage psoriasis frequently and also have access to treatments that other specialists do not. If there is joint involvement, then referral to a rheumatologist should also be considered. The main thing to keep in mind is that this is a chronic condition which unfortunately has no cure, but can be managed with a range of different treatments.

General management includes understanding the condition as well as quitting smoking, avoiding excess alcohol, and weight loss if necessary. Stress management with exercise and mindfulness is also helpful. 

There are various topical treatments which can be helpful for mild psoriasis:

  • Moisturisers

  • Coal tar preparations

  • Salicylic acid

  • Calcipotriol (a vitamin D analogue)

  • Topical steroids

  • Various combinations of the above – dermatologists often make up their own lotions and potions which can be made up by a compounded chemist

Ultraviolet (UV) therapy is a well-known form of treatment of psoriasis. Many dermatology practices offer narrowband UVB phototherapy which uses a specific wavelength of UV radiation (311-312nm) to treat numerous skin conditions. As sunlight and sunburns can flare psoriasis, this needs to be done carefully and monitored by trained nurses and doctors.

Topical treatments alone are often not enough to treat more severe psoriasis. Thankfully treatment of psoriasis has come a long way in the past decade. Several new, more targeted medications (called biologics) have been approved in recent years. Given their expense, the pharmaceutical benefits scheme (PBS) requires patients to try (and fail) other more common immunosuppressive treatments first, before they can be commenced.

Living with psoriasis can be difficult and frustrating, however, with the right approach, flare ups can be reduced and patients can life a healthy, enjoyable life.