Plaque psoriasis is by far the most common type of psoriasis, affecting 9 out of 10 sufferers. It is also known as psoriasis vulgaris. Normal skin cells are replaced every 3-4 weeks but in psoriasis this happens every 3-4 days. This is thought to be due to genetics and environmental factors.

Plaque psoriasis appears as well-defined patches of irregularly shaped, or oval, pink-red skin covered in silver-white scales (referred to as ‘plaques’). The thickness of the scales can vary. On darker skin the plaques may be grey coloured. The plaques are most often on the forearms, shins, knees, elbows, scalp, behind the ears, on the torso and around the buttocks. The skin may be itchy, but not usually sore, and can also crack – especially if the palm of the hands or soles of the feet are affected.

While it is a long-term condition, around 1 in 4 people with plaque psoriasis can find it goes away for months at a time.

Erythrodermic psoriasis is a rare, potentially life-threatening type of psoriasis. It is thought be caused by genetics and some environmental factors. Erythrodermic psoriasis can develop gradually or come on suddenly – spreading across the whole body to affect more than 90% of the skin. You might also feel unwell with fatigue, fever and develop swollen lower legs. If you have these symptoms you should go straight to A&E.

Erythrodermic psoriasis can happen in anyone with plaque psoriasis but can be triggered by factors like infections or skin irritants.

Flexural psoriasis, also known as inverse psoriasis, affects the creases and folds of your skin. It can cause itchy, red, glazed areas in your skin folds, such as the armpits, groin, genitals, buttocks and under the breasts. Sweat or rubbing the affected skin can cause further irritation. The condition is more common in people who are overweight, immobile or elderly. You may also find you’re more prone to developing yeast infections in the same areas as your flexural psoriasis.

This form of psoriasis is also known as ‘raindrop’ or ‘droplet’ psoriasis because it looks like droplets on the skin. Certain people who have had guttate psoriasis will develop chronic plaque psoriasis later in their life.  Guttate Psoriasis most frequently occurs in children and teenagers, usually after a throat infection caused by streptococcal bacteria. Even though it may be caused by an infection, guttate psoriasis is not contagious. The condition develops over the course of a week, with many small, raised, scaly patches that are round or oval and pink or red appearing all over the body.

Nail psoriasis affects the fingernails and toenails with a range of symptoms. Nails may turn orange-yellow, become pitted, start to come away from your skin or disintegrate. The condition is more likely to affect your fingernails than your toenails. Nail psoriasis can happen in anyone with psoriasis, but it is particularly common if you also have arthritis-associated psoriasis.

This is a rare type of psoriasis where there are pus-filled spots on or surrounded by red skin. There are two main types of pustular psoriasis: generalised and localised. Around 5% of people with psoriasis experience localised pustular psoriasis, but in rare cases this can be generalised which can be life threatening. Localised pustular psoriasis (also known as palmoplantar psoriasis) appears as yellow-brown blisters, known as ‘pustules’, on your palms and soles along with scaly skin and redness on your toes and fingertips. In generalised pustular psoriasis, redness spreads quickly over your skin followed by the development of multiple white pustules that group together to form large areas of pus. These blisters are not contagious.

Pustular psoriasis is more common in those who have, or have had, plaque psoriasis. However, you can develop it even if you’ve never had psoriasis before. Triggers range from stress, certain medicines and infections to pregnancy or too much sun. Localised pustular psoriasis usually occurs in those aged 20-60, particularly if you smoke.

Scalp psoriasis looks like plaque psoriasis, but affects your scalp. Your hair traps the scale making it hard to rub away, and as a result the plaques can become thick. Some people find that only parts of their scalp is affected, while for others it’s across their whole scalp. In some cases scalp psoriasis can even cause bald patches, but the hair will normally grow back. Up to 9 out of 10 people with psoriasis develop it on their scalp. Some people may experience itchy scalp, a feeling of tight skin and occasionally soreness if the skin cracks.