Psoriasis is a chronic skin disorder in which skin cells multiply at a rate which is significantly faster than normal. The life cycle of a skin cell will usually take around 28 days, starting as a new cell at the deepest layer before making its way up to the surface before dying and flaking off.

In an individual affected by psoriasis, the life cycle of the skin is sped up dramatically, with the sheer volume of cells pushing others which have not fully matured to the surface where they form red, crusty patches covered in silvery-white scales.

These patches are non infectious and can affect any part of the body but most commonly occur on the lower back, knees and elbows and result in itching, burning and pain.

The severity of the patches will vary from person to person and for some people will only cause minor irritation whilst for others will affect their overall quality of life.

It is thought that the condition affects approximately 2% of people in the UK, usually setting in between the ages of 11 and 45 and reoccurring in cycles at various times throughout life.

Cause of psoriasis 

Genetics are thought to play a role in psoriasis with one in three individuals affected also having a close relative with the condition. Though the reason for this is yet to be discovered, research has shown that there are a number of different genes which are linked to psoriasis development and experts believe that certain combinations could make certain individuals more vulnerable to the condition.

Types of psoriasis

Listed below you will find the various different types of psoriasis. Though it is extremely rare, individuals can be affected by more than one form at a time, and in some cases one type may change into another or will increase in severity.

  • Erythrodermic psoriasis – This is a rare form of the condition and affects the vast majority of skin on the body, causing intense and painful burning and itching. In severe cases it can result in your body losing essential proteins and fluids which can lead to infection, malnutrition, dehydration, hypothermia and heart failure.
  • Guttate psoriasis – Characterised by small drop shaped sores on the arms, legs, scalp and chest, this form of psoriasis commonly occurs after a streptococcal throat infection and may disappear completely after it has run its course (though some individuals do go onto develop plaque psoriasis).
  • Inverse psoriasis Smooth red patches occur in crease and folds of the body such as behind the knees, between the buttocks, in the armpits and under the breasts. Symptoms are worsened by sweating and friction so it can become particularly uncomfortable in hot weather.
  • Plaque psoriasis – Accounting for around 80% of cases, this is the most common form of psoriasis. Symptoms consist mainly of very dry, red patches on the skin which are covered in silvery-white scales and are known as plaques. Whilst they can occur on any part of the body they are most often seem on the lower back, scalp, knees and elbows and are generally either itchy, sore or both.
  • Pustular psoriasis – One of the rarer forms of the condition which see's pus-filled blisters appear on the skin. There are various forms of pustular psoriasis, generalised pustular psoriasis, palmoplantar pustular psoriasis and acropustulosis, all of which affect different areas of the body.
  • Nail psoriasis – Small dents and pits develop in the nails and cause them to discolour and grow abnormally. Nails do often separate from the nail bed and in severe cases may crumble.
  • Scalp psoriasis – Red patches covered in silver scales appear on areas of the scalp. For some it may cause itching and hair loss and for others it causes very little to no discomfort.

Psoriasis triggers

Similarly to many other chronic skin conditions, psoriasis can worsen if it is provoked by something which your body does not react well too. If you are able to identify these triggers then you may be able to prevent psoriasis flare-ups in the future so it may be a good idea to note down what you eat, how you feel and the severity of your psoriasis so that you are able to see any emerging patterns. Though not everyone is going to have the same trigger, some of the most common include the following:

  • alcohol
  • smoking
  • skin injury – a cut, scrape, bite or sunburn
  • immune disorders – HIV infection or other immune disorders can trigger psoriasis for the first time
  • medication - certain medicines such as anti-inflammatory medicines such as ibuprofen, ACE inhibitors for blood pressure and beta blockers for congestive heart failure can trigger a flare-up
  • stress – research has found that as many as 80% of individuals experiencing flare-ups report a recent emotional trauma.
  • throat infection – this can lead on to guttate psoriasis.


When it comes to diagnosing psoriasis, a doctor will usually be able to do this based on the appearance of the skin alone. However, in rare cases where other skin conditions need to be ruled out or when the exact type of psoriasis needs to be determined, a small sample of skin can be taken for a biopsy.

Though there are currently no cures for psoriasis, there are a range of treatments which can help to make the symptoms more manageable as well as reducing the appearance of skin patches.

Most people will find that they can obtain effective treatment from their GP but if you have not responded well to the treatment given, or if symptoms are particularly severe then your GP may refer you to a dermatologist.

There are a wide range of treatment options available for psoriasis sufferers and each are prescribed according to the area of skin affected and the severity of the psoriasis. The three most commonly prescribed treatment categories are as follows:

  • Oral medicine or injection medicine – Works to reduce the production of skin cells.
  • Phototherapy – Exposes the skin to specific ultraviolet light.
  • Topical – Creams and ointments which can be applied to the skin.

The different treatments can be used in combination and may need to be reviewed on a regular basis in order to ensure they remain effective.

Nutrition and psoriasis

Much research has been undertaken in relation to the role played by diet in psoriasis, though little scientific evidence has emerged to support the notion that good nutrition could improve symptoms. It goes without saying that everyone should endeavour to eat a good diet full of healthy and nutritious foods no matter what conditions they may or may not have, but some psoriasis sufferers have reported that eliminating certain foods from their diet has actually helped certain symptoms to improve.

Whilst there is no one diet that will suit everyone, individuals suffering from psoriasis are generally advised to steer clear of manufactured foods containing a high volume of chemical additives and preservatives which may cause irritation or heightened sensitivity.

A common irritant among individuals suffering from psoriasis seems to be alcohol. Though the exact reason for this is unknown, alcohol has long since been attributed with dehydration of the body, including the skin, so excess amounts could result in psoriasis becoming drier.

If you do notice that your symptoms are worsening after drinking or eating anything in particular then a GP may suggest you try removing whatever it is from your diet and see if you experience an improvement. If you are not sure exactly what it is that is causing you problems then do a bit of investigating and keep a food diary which records what you eat, when you eat it and how is effects your psoriasis. For some, a special diet or removing certain foods and drinks will work extremely well, but for others it will have little to no effect.

It is not possible for a diet to cure psoriasis completely but it may be able to keep symptoms manageable and under control.

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