Psoriasis is a term derived from the Greek word psōra which means itch and is a common, chronic inflammatory skin condition which affects 1-3% of the UK population and about 80 million people worldwide. Psoriasis is a non-infectious, multi-factorial condition which involves genetics, the immune system and environmental triggers that results in inflammation, itching and the formation of red, raised plaques, with silvery-white scales and well-defined edges on the surface of the skin. These plaques vary in both shape and size and can dry and crack making the skin feel sore.

Psoriatic lesions can appear anywhere on the body but most commonly affect the scalp, lower back and the outer surfaces of the knees and elbows. Patients will experience periods of flare-ups, when individual triggers aggravate their skin, and remissions.

There are many different types of psoriasis and the most common ones are described in Table 1 along with their characteristics.

TypePrevalanceCharacteristicsCommon Areas Affected
Psoriasis Vulgaris
or Chronic Plaque Psoriasis
80% of people with psoriasis have this type
  • Red, raised, inflamed skin with
    silvery-white scales and sharp edges (plaques) which may be itchy

  • Plaques are usually symmetrical appearing on both knees or elbows and vary in size from 1cm to several cm
Knees or shins


Lower Back

Guttate PsoriasisAffects about 18% of psoriasis sufferers and is most often seen in children and young adults usually after a streptococcal throat infection such as tonsillitis
  • Many, small (less than 1cm diameter)
    pink-red, droplet-like patches which may clear within a couple of weeks, even without treatment

  • Sometimes it disappears and is never seen again however in other instances the patient goes on to develop chronic plaque psoriasis


Upper arms

Inverse Psoriasis or Flexural PsoriasisTends to be seen more in older people and women
  • Lesions that are bright red, smooth, shiny and have no scales

  • Occurs in the flexures

  • Made worse by sweating and rubbing

Under the breasts


Between buttocks

Pustular PsoriasisThis is an uncommon form which mainly appears in adults and more so in women
  • Yellow or brown pus-filled bumps which are surrounded by red skin that is tender
There are two unrelated types:

Palmo-plantar pustular psoriasis which affects the palms of the hands and soles of the feet

Generalised pustular psoriasis which can affect any part of the skin and is widespread. A very serious condition requiring urgent treatment by a specialist
Erythrodermic PsoriasisRare but serious (potentially life-threatening)

In the UK there are about 200-300 new cases every year.
  • Inflamed, widespread redness with merged plaques (so they aren’t noticeable)

  • Painful, skin feels warm and the person may have a fever

  • The condition interferes with the skins capacity to control temperature, protect against infections can can cause dehydration and heart failure
Most of the patients body
Nail PsoriasisAffects up to 50% of those with psoriasisChanges seen in the nails include:

  • Separation from the nail bed

  • Irregular pitting on the surface

  • Thickening

  • Discolouration (looks like a drop of oil under the nail plate)
Finger nails (more common)

Toe nails
Psoriatic ArthritisOccurs in about 10 - 20% of psoriasis sufferers
  • Inflammation, pain and joint swelling but other areas can also be affected



Lower Back


Table 1: Different types of Psoriasis and their Characteristics

The most common form of psoriasis is chronic plaque psoriasis which affects about 80% of psoriasis sufferers. Psoriasis affects men, women and children of all races although it has a higher prevalence in Caucasians compared to Non-Caucasians e.g. prevalence is 1.3% in African Americans, 0.1% in Japanese and 2.5%  in Caucasians. Psoriasis can happen at any age but there appear to be two peaks of onset, 15-20 years and 55-60 years with 10-15% of children developing the condition before the age of 10.

About one third of those suffering from psoriasis have a family history however it is a multi-genetic condition, involving several genes (effecting an individual’s type of psoriasis and response to treatment) so whether a person develops psoriasis or not is complex.

globe_bullet People with early onset psoriasis tend to have more of a family history of psoriasis.

globe_bullet If one parent has psoriasis there is about a 25% chance that their child will develop it however if both parents have it this goes up to 60%.

globe_bullet If neither parent has psoriasis but their child develops it then there’s a 20% chance that a sibling will also develop it – this is because psoriasis can skip a generation.

The exact cause of psoriasis is unknown however it is a multifactorial condition involving genetics, the immune system and environmental triggers.

Our skin is made up of three layers:

globe_bullet    Epidermis

globe_bullet    Dermis

globe_bullet    Hypodermis or subcutis

The epidermis, the outer skin layer, consists of five smaller layers: the stratum basale, the stratum spinosum, the stratum granulosum, the stratum lucidum and the uppermost layer the stratum corneum, which is the skin barrier.

The predominant cells in the epidermis are the keratinocytes which are produced by cellular division in the stratum basale. These keratinocytes move up through the epidermal layers undergoing a terminal differentiation to form corneocytes (anucleated keratinocytes), replacing those that are continually being shed from the stratum corneum. This process usually takes 21 to 28 days on average.
In patients suffering from psoriasis not only do the keratinocytes over proliferate resulting in double their numbers in the stratum basale, their rate of turnover is faster (3-4 days). This faster turnover means that live keratinocytes reach the skin surface where they join corneocytes forming clumps or plaques. It is thought that a malfunction of the immune system results in T-cells attacking healthy skin cells causing inflammation and keratinocytes to rise to the surface at this faster rate (3-4 days). There are also vascular changes whereby blood vessels proliferate near the plaque surface so any scratching or removal of plaques results in pinpoint bleeding, known as Auspitz sign. As well as this there is also abnormal differentiation of keratinocytes and hyperkeratosis occurs which causes the skin to thicken resulting in raised psoriatic plaques.

Some patients will not know what triggers their flare-ups or makes their psoriasis worse whilst others will. Not only do triggers vary from person to person but so does an individual’s response to them however, helping patients to identify their triggers would mean that they could avoid them and so reduce flare-ups.

Common triggers include:

globe_bullet Anxiety & Stress – such as a divorce or a bereavement. Managing the stress may help patients.

globe_bullet Skin injury – due to scratching, cuts, rubbing and sunburn (known as Koebner Phenomenon).

globe_bullet Excess Alcohol – it may benefit patients if they reduce the amount of alcohol that they consume.

globe_bullet Smoking – quitting may help.

globe_bullet Sunlight – although most people find that sunlight helps with their psoriasis in 10% of sufferers it can make it worse.

globe_bullet Infections – especially a sore throat (tonsilitis) caused by the bacteria streptococcus (mainly in children and young adults).

globe_bullet Medication – including Beta-blockers, ACE inhibitors, lithium, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), certain antibiotics and Anti-malarials (those with chloroquine).

globe_bullet Hormonal changes – during puberty and menopause although some people find that during pregnancy their symptoms get better.

Symptoms of psoriasis will vary depending on the severity of the condition and the type of psoriasis.  In mild cases there are small areas of rash and as the severity of the psoriasis increases symptoms will include inflamed, itchy skin with raised, red, scaly plaques, which can dry and crack making the skin feel sore.

50% of people suffering from psoriasis also experience changes to their nails which can include them separating from the nail bed, irregular pitting on their surface, splitting easily, thickening and changing colour (translucent yellow-red discolouration).

Some sufferers have swollen, painful and stiff joints – this is called psoriatic arthritis.

Although there is currently no cure for psoriasis, treatments can help to improve symptoms and the appearance of patches. The first step in managing a patient’s condition would be for them to avoid any known triggers unfortunately this is not that easy as certain triggers are unavoidable such as puberty and menopause and in some cases sufferers cannot identify what their triggers are.

The severity of psoriasis can be classed as:

globe_bullet Mild – affects 80% of sufferers, is easily controlled, with few patches and involves less than 3% of a person’s body surface area.

globe_bullet Moderate – affects 15% of sufferers, can normally be self-managed under the supervision of a healthcare professional with between 3% – 10% of skin area being affected.

globe_bullet Severe – affects 5% of sufferers, may not be responsive to treatment or be self-managed and affects over 10% of body surface area.

Treatments will vary depending on the site, type and severity of the psoriasis however, as emollients such as AproDerm® help manage the severity of the psoriasis they form the basis for all treatments. They should always be used even when your patient’s psoriasis has improved as this reduces the risk of flare-ups.

Emollients like the AproDerm® Range are moisturising treatments which are used to break the dry skin cycle and to maintain the smoothness of the skin. They work by; helping skin retain water, moisturising the skin, easing itching, reducing scaling, softening cracks and protecting the skin. AproDerm® Emollient Cream and AproDerm® Colloidal Oat Cream are therefore leading symptomatic treatments for psoriasis, where a patients skin has become reddened, dry, itchy and cracked. They work by:

globe_bullet  Forming a protective layer over the skin surface, trapping in water which then goes into the corneocytes, rehydrating them and causing them to swell again. AproDerm® also penetrates through the upper layers of the stratum corneum filling the gaps between the corneocytes so that they are once again surrounded (mimicking the lipid lamellae) thus restoring the skin barrier so that irritantspathogens and allergens are kept out whilst keeping in water and other substances. Rehydration of the skin helps relieve the itching, irritation, discomfort and dryness associated with psoriasis and softens psoriatic patches, which makes them less likely to crack and cause the skin to become sore.

globe_bullet  Removing the scales, which helps with the application of other topical psoriasis treatments. AproDerm® should be applied 30 minutes before these treatments and in very mild cases of psoriasis the patient may only need AproDerm®.

globe_bullet  AproDerm® Colloidal Oat Cream has a number of additional benefits and mechanisms of action. Formulated with active colloidal oatmeal which is proven to protect and restore the skin’s surface, oatmeal has also been used for centuries as a soothing agent to relieve itch and irritation and has been clinically proven to improve dryness, scaling and roughness. With its direct anti-inflammatory and anti-oxidant activities, colloidal oat restores the epidermal barrier damaged by psoriasis. AproDerm® Colloidal Oat Cream also has humectant, buffering and cleansing effects.

In order to achieve maximum benefit from AproDerm® patients should apply it regularly, liberally and at least three times a day in gentle, downward strokes following the direction of hair growth. Once their condition has improved they should continue applying AproDerm® in order to reduce the risk of flare-ups.

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