What is psoriasis?

Psoriasis is a chronic skin disease that affects 1.5-2% of the population in the UK. 60% of those with psoriasis need to see a Consultant Dermatologist for specialist advice at some stage for their condition.

It is a disorder of the immune system that causes inflammation in the skin. As a result, there is redness and itching, and skin cells grow too quickly, resulting in thick, scaly patches on the skin.There are several types of psoriasis, each with unique clinical features and potential causes. This article will provide an overview of the different types of psoriasis, their causes, and their clinical characteristics.

Types of Psoriasis:

  • Plaque Psoriasis. This is the most common type of psoriasis, accounting for about 90% of cases. It is characterised by raised, red patches covered with silvery-white scales. These patches can appear anywhere on the body but are most commonly found on the elbows, knees, scalp, and lower back.
  • Guttate Psoriasis. Small, teardrop-shaped spots on the arms, legs, and trunk characterise this type of psoriasis. It is often triggered by a bacterial infection such as strep throat and is more common in children and young adults.
  • Inverse Psoriasis (also known as Flexural Psoriasis). Inverse psoriasis appears as smooth, red patches in the skin folds, such as the armpits, groin, genitals, and under the breasts. It can be triggered by friction and sweating and is more common in people who are overweight.
  • Pustular Psoriasis. This type of psoriasis is characterised by pus-filled blisters on the hands and feet or all over the body. It can be triggered by certain medications or by suddenly stopping the use of steroids.
  • Erythrodermic Psoriasis. Erythrodermic psoriasis is the most severe form of psoriasis and is characterised by widespread redness and peeling of the skin. It can be triggered by severe sunburn, medication, or other triggers.

Impact of Psoriasis

Psoriasis can significantly impact individuals, causing functional, psychological, and social challenges that can lead to reduced employment opportunities and income. This is due to a range of factors, including skin-related symptoms such as chronic itching, scaling, bleeding, nail involvement, difficulties with treatments, and the burden of living with a highly visible and stigmatised skin condition.

However, even those with mild symptoms report a significant impact on their quality of life. Furthermore, research suggests that individuals with severe psoriasis may face an increased risk of cardiovascular disease, lymphoma, and non-melanoma skin cancer.

Causes of Psoriasis

The exact cause of psoriasis is not yet fully understood. However, it is known to be a complex autoimmune disease that results from the interaction of genetic and environmental factors. The following are some of the factors that are believed to contribute to the development of psoriasis:

  • Genetics. Psoriasis is known to run in families, suggesting a genetic component to the disease. Specific genes have been identified that are associated with an increased risk of developing psoriasis.
  • Immune System. Psoriasis is believed to result from a malfunction of the immune system, in which the body’s defences mistakenly attack healthy skin cells.
  • Environmental Triggers. Certain environmental factors can trigger the onset or exacerbation of psoriasis. These can include infections such as streptococcal infections, stress, injury to the skin, certain medications such as beta-blockers, and exposure to cold weather or sunlight (though sunlight improves psoriasis for 90% of people).

Clinical Features of Psoriasis

The clinical features of psoriasis can vary depending on the type and severity of the disease. However, some common clinical features include the following:

  • Red, Raised Patches. Psoriasis typically appears as red, raised patches of skin covered with silvery-white scales. These patches can be itchy, painful, and may crack and bleed.
  • Nail Changes. Psoriasis can cause changes to the nails, including pitting, discolouration, and separation from the nail bed. About 50% of those with plaque psoriasis have nail changes.
  • Joint Pain. Psoriasis can also affect the joints, causing pain, stiffness, and swelling. This is known as psoriatic arthritis and can occur in up to 15% of people with psoriasis.
  • Dry, Cracked Skin. Psoriasis can cause the skin to become dry and cracked, particularly in the hands, feet, and scalp.
  • Scalp Psoriasis. Psoriasis can affect the scalp, causing redness, itching, and flaking. This can lead to hair loss and can be particularly distressing for those affected.

Treatment for psoriasis

There is no cure for psoriasis, but several treatment options can help manage symptoms and reduce the frequency and severity of flare-ups. The choice of treatment will depend on the type and severity of psoriasis and the individual’s medical history and lifestyle factors.

Topical Treatments for psoriasis

Topical treatments are usually the first line of treatment for mild to moderate psoriasis. They are applied directly to the affected skin and can help reduce inflammation and scaling. Topical treatments include corticosteroids, vitamin D analogues, and topical retinoids. Over-the-counter moisturisers and emollients can also help relieve dryness and itching associated with psoriasis.

Phototherapy for psoriasis

Phototherapy involves exposing the skin to controlled amounts of natural or artificial light. It can be an effective treatment option for moderate to severe psoriasis. The two main types of phototherapy are narrowband UVB and PUVA therapy. Narrowband UVB uses a specific wavelength of light that effectively treats psoriasis, while PUVA therapy combines a photosensitising medication with UVA light.

Systemic Treatments for psoriasis

Systemic treatments are medications taken orally or injected, usually reserved for moderate to severe psoriasis that has not responded to other treatments. Systemic treatments include biologics, which target specific immune system components involved in psoriasis, and oral medications, such as acitretin, methotrexate and cyclosporin.

Biological treatments are a newer class of medications that target specific immune system components involved in psoriasis. As they are expensive, they are typically reserved for moderate to severe psoriasis that has not responded to other treatments. Biological treatments include monoclonal antibodies and fusion proteins, which are designed to block the activity of specific molecules involved in the inflammatory response.

One example of a biological treatment for psoriasis is adalimumab, which targets tumour necrosis factor-alpha (TNF-alpha), a molecule involved in the immune response. Adalimumab is administered by injection under the skin and is typically given every other week. Other biological treatments include etanercept, infliximab, efalizumab, ustekinumab, ixekizumab and secukinumab.

Biological treatments are generally well-tolerated, but they can have side effects like all medications. Common side effects include injection site reactions, upper respiratory tract infections, and headaches. More severe side effects, such as an increased risk of infections, have also been reported.

Lifestyle changes for psoriasis

In addition to medical treatments, lifestyle changes can help manage psoriasis symptoms. These include:

  • Avoiding triggers such as stress, smoking, and alcohol
  • Eating a healthy, balanced diet and maintaining a healthy weight
  • Exercising regularly
  • Getting enough sleep
  • Keeping the skin moisturised and avoiding harsh soaps and detergents

The choice of treatment will depend on the type and severity of psoriasis and the individual’s medical history and lifestyle factors. However, a comprehensive treatment plan that incorporates a combination of these approaches can help manage symptoms and improve the overall quality of life for people with psoriasis.

When to see a Dermatologist for Psoriasis

Here are some signs that it may be time to see a dermatologist for psoriasis:

  1. Your symptoms are getting worse. If your psoriasis symptoms are getting worse despite using over-the-counter or GP-prescribed treatments, it may be time to see a dermatologist. A dermatologist can evaluate your condition and recommend stronger treatments, such as prescription medications or phototherapy.
  2. Your psoriasis is affecting your quality of life. Psoriasis can significantly impact a person’s quality of life, affecting their physical, psychological, and social well-being. If your psoriasis affects your daily life, it may be time to seek professional help. A dermatologist can work with you to develop a comprehensive treatment plan that meets your specific needs.
  3. You have joint pain or swelling. Psoriasis can sometimes be associated with psoriatic arthritis, a type of arthritis that affects some people with psoriasis. If you have joint pain or swelling in addition to your psoriasis symptoms, it is important to see a dermatologist or rheumatologist for evaluation and treatment.
  4. You are experiencing side effects from your current medication. If you are experiencing side effects from medication, it is important to speak with a dermatologist who can evaluate your condition and recommend alternative treatments.
  5. You have a history of skin cancer. If you have a history of skin cancer or are at high risk for skin cancer, it is important to see a dermatologist for regular skin cancer screenings. Psoriasis can increase the risk of certain types of skin cancer, so it is important to monitor your skin for changes.

How to see a dermatologist for psoriasis

If you or your child has psoriasis, and you would like diagnosis and treatment, then please see one of our Dermatologists, who will be happy to help. You can make an appointment here.

Additional reading

Further information on dermatitis can be found here: