Psoriasis: Causes, types and treatments explained by a dermatologist

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Dr. Shreya Andric is a dermatologist based in Sydney. She is passionate about skin health and her mission is to educate the public on how to care for their skin, and also clear up the vast amount of misinformation out there on this topic.

When not at work, Shreya is kept busy by her two young children and loves to spend time with family, friends and occasionally get to a pilates or boxing class!

While Dr. Andric has independently chosen the products that appear in this article, she does not receive revenue from the links. Some of the links may return revenue to Yahoo Lifestyle Australia.

Dr Shreya Andric is a Sydney-based dermatologist on a mission to educate people on how to look after their skin. Photo: supplied.
Dr Shreya Andric is a Sydney-based dermatologist on a mission to educate people on how to look after their skin. Photo: supplied.

Psoriasis is a chronic inflammatory skin condition that affects 2-4 percent 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 percent of patients having family members with psoriasis.


What is 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.

Normal skin layer and skin when plaque psoriasis signs and symptoms appear. illustration about dermatology diagram.
With psoriasis, skin cells don’t have a chance to fall off resulting in a build-up of scale. Photo: Getty Images.

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.

What causes psoriasis?

Psoriasis is thought to be due to multiple different factors. Genetics plays a big role in this condition and a person’s genetic profile (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 percent (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.

Close-up of young woman scratching her arm while sitting on the stool in the home kitchen.
Psoriasis can be genetic but it is not contagious. Photo: Getty Images.

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

  • Psoriatic arthritis (can occur in up to 40 percent 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

Treating psoriasis

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

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 that 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 that 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

doctor spends psoriasis treatment using ultraviolet lamps and phototherapy. Skin diseases, eczema, dermatitis, shingles, peeling
Ultraviolet (UV) therapy is a well-known form of treatment of psoriasis. Photo: Getty Images.

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 live a healthy, enjoyable life.

Dermeze Treatment Cream 100g, $7.49 from Chemist Warehouse. Photo: Chemist Warehouse.
Dermeze Treatment Cream 100g, $7.49 from Chemist Warehouse. Photo: Chemist Warehouse.

General tips for dry, wintry skin

As the weather cools, I have more and more people coming to see me with dry, scaly skin.

Cooler temperatures and low humidity levels, combined with long, hot showers and soap-based products are responsible for this and can also cause flares of some pre-existing skin conditions.

When looking for a body moisturiser, you might choose something thicker that comes out of a tube or a tub, as a formulation coming through a pump is likely too thin. The Dermeze Treatment Cream is a great choice.

Lips and hands are two of the first areas to show signs of dryness. I often recommend the Dermal brand lip balms as they are super hydrating without being sticky.

Neutrogena Norweigan Formula Hand Cream is my go-to for dry hands.

And don't skip sunscreen just because it's overcast — UVA is present year-round and is able to penetrate through the clouds.

Some sunscreens can be quite hydrating and are a great option for the winter months as they can be used instead of a moisturiser eg. UltraViolette Supreme Screen, QV face cream.

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