Psoriasis is an inflammatory disease that commonly affects the scalp, torso, elbows, knees and fingernails. It is a non-contagious chronic disease that can cause great discomfort. It most commonly presents as sharply defined red, dry plaques of thickened skin covered by a silvery, flaky surface and can also present as a weepy or pustular condition.
Psoriasis can affect people of all races and ages, however, most patients are first diagnosed in their early adult years. Guttate psoriasis, which flares up following a viral or bacterial infection, normally affects children and young adults.
In psoriasis, the keratinocytes of the skin multiply very rapidly and travel from the bottom layer of the epidermis to the surface in approximately 4 days. The skin cannot shed these cells quickly enough, so they build up, leading to thick, dry patches or plaques. Silvery, flaky areas of dead skin build up on the surface of the plaques before being shed. The skin layer underneath the epidermis (dermis), which contains the nerves and blood and lymphatic vessels, becomes red and swollen.
The cause of psoriasis is unknown, although it is well accepted that there is an underlying genetic component which, when triggered, causes the immune system to produce an excessive number of skin cells. As such it has been termed an auto-immune skin disorder.
There are four Primary triggers that start or activate psoriasis.
|Koebner Phenomenon||Injury or trauma to the skin i.e. operations, bites, cuts, abrasions etc.|
|Systemic Infections||Tonsillitis, Shingles and some viral and bacterial infections.|
|Drug Interaction||Taking or cessation of certain drugs such as steroids, lithium, antimalarials, anti-inflammatories, some blood pressure medications (Beta-Blockers) and antibiotics.|
|Stress||Anxiety and worry|
Secondary triggers play a role in the continued exacerbation of the condition. In his research, Dr Tirant’s research discovered that such factors were often related to lifestyle, dietary and chemical exposure.
To know more on triggers, read our blog – What triggers psoriasis?
Types of Psoriasis
|Plaque (chronic)||This is the most common type of psoriasis, affecting 90% of those who live with the condition.It presents as dry, red, raised spots (lesions) covered in silvery white scales. It usually appears on the elbows, knees, scalp, or lower back, although it can be found anywhere on the body, including the genitals.|
|Pustular||This form of psoriasis develops quickly. It takes the form of little blisters filled with pus (pustules) and is normally found on the hands, feet and fingertips. The blisters appear just hours after the skin becomes red and tender and can be very itchy and painful.|
|Psoriatic nails||This type of psoriasis affects the nails in approximately 5% of psoriasis sufferers. It can start before any skin symptoms appear. The nail plate may be pitted with small surface depressions and discolouration (yellowish – white). Often there is a thick build-‐up of keratin under the nails. This causes the nails to lift and separate from the nail bed. Nails are often brittle and can easily break.|
|Guttate||This type of psoriasis usually appears suddenly, often following a viral or bacterial infection such as streptococcal pharyngitis (strep throat). It appears as small, water/drop- shaped red spots on the trunk, arms, legs and scalp. The spots are not flaky and not as thick as typical plaques are. This type of psoriasis affects mainly children and young adults.|
|Palmo-Plantar||This type of psoriasis affects the palms of the hands and soles of the feet. It can appear as dry and thickened skin, silvery in appearance or in the pustular form.|
|Psoriatic Arthritis||This type of arthritis affects approximately 5% to 7% of psoriatics and is more frequent in those who have psoriatic nails or pustular psoriasis. In many cases, the arthritis may be present for years before any skin issues appear. Symptoms include fatigue, morning stiffness, articular pain and swelling.|
|Flexural or Inverse||This type of psoriasis is only found in the folds and creases of the body. It tends to be moister than any other form and can be quite uncomfortable.|
|Erythrodermic||This is the least common form of psoriasis. It results in inflammation, itching and a painful red rash that may peel. It often covers the entire body and is sometimes accompanied by chills and fevers.Erythrodermic psoriasis can be triggered by severe sunburn, withdrawal from systemic treatment or any other form of psoriasis that is not well managed. People with this type of psoriasis should seek immediate medical attention because it can lead to dangerous protein and fluid loss, swelling, infection or pneumonia. It normally requires hospitalisation.|