Getting under the skin of psoriasis

Woman itching skin: Psoriasis skin condition

Psoriasis affects around 2% of the population. Although seen as a skin condition, it is an immune condition which can have a physical and psychological impact.

Psoriasis is an immune condition which affects the skin, and sometimes the joints. It causes the skin replacement process to accelerate meaning that the usual process of skin replacement, which typically takes three to four weeks, can happen in just a few days.

This acceleration results in an excess build-up of skin which usually presents as flaky or scaly patches that can be red, dark, sore, or itchy.

Anyone can experience psoriasis. It affects approximately 1.8 million people in the UK and can occur at any age, although the Psoriasis Association says that there are two ‘peaks’ from late teens to early 30s and between 50 and 60.

“It is believed that psoriasis begins in the immune system when t cells are triggered and become overactive”

Patterns of psoriasis

According to the British Skin Foundation, there are several ‘patterns of psoriasis’.
These are:

  • Chronic plaque psoriasis, the most common form of psoriasis. Plaques usually present on the knees, elbows, trunk, scalp, behind ears and between the buttocks, although they can occur elsewhere, too.
  • Guttate psoriasis consisting of small spots scattered over the trunk and limbs. The spots can be pink or red on fair skin types and darker on darker skin types. It can be caused by streptococcus.
  • Palmoplantar psoriasis which affects the palms of the hands and soles of the feet. It may appear at other parts of the body, too.
  • Pustular psoriasis, a rare form of psoriasis where tiny, yellow, pus-filled spots (pustules) appear on top of very red or darkened skin. Pustular psoriasis can be localised or generalised and can flare up rapidly. Flare ups can lead to hospitalisation for treatment.
  • Erythrodermic psoriasis is an aggressive and rare type of psoriasis. It affects nearly all of the skin and, in some cases, can also require hospital admission for treatment.
  • Nail psoriasis can also present in up to half of people with psoriasis. It can cause nail indentations, areas of discolouration, separation of the nail from the bed, thickening of the nails or destruction of nails.

Some people may also experience psoriatic arthritis which, as the name suggests, is a type of inflammatory arthritis that affects some people who have psoriasis. It can make joints stiff, swollen and painful.

Key stats

What causes psoriasis?

It is believed that psoriasis begins in the immune system when T cells are triggered and become overactive, although the exact trigger is still unknown. According to the Psoriasis Association, new research has found that T cells act as if they were fighting an infection or healing a wound. They produce inflammatory chemicals which can lead to rapid skin cell growth causing plaques to form.

Psoriasis can, but doesn’t always, run in families, leading some to believe it has its basis in genetics. It is not contagious.

Psoriasis triggers

Psoriasis flare-ups can be caused by a range of factors from environment to health. Understanding what triggers a flare up can help people to manage their condition. Common triggers are:

  • Excessive amount of alcohol
  • Smoking
  • Stress
  • Injury to the skin including cuts and scrapes
  • Sunburn
  • Hormonal changes, particularly in women
  • Medication, including some anti-inflammatories, antimalarial medicines, and ACE inhibitors
  • Throat infection, such as streptococcal throat infection can cause guttate psoriasis to develop, usually in children and young adults
  • Other immune disorders, including HIV.

Source: NHS.UK

“The National Institute for Health and Care Excellence recommends topical therapy as
first-line treatment with follow-up review to evaluate effectiveness”

Psoriasis treatments

Treatment will depend on the type of psoriasis, the severity of the condition and what works for the individual. It can be a trial and error process to get treatment right, leading to frustration for those living with the condition.

Initially individuals should contact their GP to discuss treatments, they may then be referred to a dermatologist in more severe cases.

UK charity, the Psoriasis and Psoriatic Arthritis Alliance (papaa) lists the different types of treatments as:

  • Emollients
  • Antifungals
  • Antihistamine
  • Coal Tar
  • Steroids
  • Retinoids
  • Dithranol
  • Immunosuppressant therapies
  • Phosphodiesterase 4 inhibitors
  • Biologic Agents.

The National Institute for Health and Care Excellence recommends topical therapy as first-line treatment with follow-up review to evaluate effectiveness. Vitamin D may also be prescribed in specific circumstances.

If topical treatments do not offer adequate control of the condition, a referral to a specialist is recommended where phototherapy or systemic therapy can be considered.

Phototherapy involves exposing the skin to specific types of ultraviolet light, either narrowband ultraviolet B or psoralen with local ultraviolet A (PUVA). Systemic therapy is divided into biological and non-biological therapy.

Treatments for psoriatic arthritis include:

  • Topical analgesics
  • Non-steroidal anti-inflammatory drugs (NSAIDS)
  • Corticosteroids
  • Disease modifying anti-rheumatic drugs (DMARD)
  • Biologics.

Recent developments in psoriasis

Celltrion Healthcare announced in June that the Committee for Medicinal Products for Human Use of the European Medicines Agency has recommended expanding the existing marketing authorisation for the subcutaneous (SC) formulation of Remsima® (CT-P13) in an additional five indications including for the treatment of patients with psoriatic arthritis and psoriasis. The subcutaneous formulation can be administered by patients giving flexibility and control.

In early June, the Janssen Pharmaceutical Companies of Johnson & Johnson announced new data from two Phase 3 clinical trials, DISCOVER-1 and DISCOVER-2, which showed that TREMFYA®‚ (guselkumab) demonstrated improvements in multiple clinical outcomes including joint symptoms, skin symptoms, soft tissue inflammation, physical function and reduction in radiographic progression at week 52 in adult patients with active psoriatic arthritis (PsA). Guselkumab is currently not licensed for the treatment of PsA and is undergoing evaluation for this use by the European Medicines Agency.

Key players

The key players operating in the psoriasis treatment market are:

  • Amgen Inc.
  • Sun Pharmaceutical Industries Ltd.
  • MSD.
  • Eli Lilly and Company.
  • UCB S.A.
  • Novartis AG.
  • LEO Pharma A/S.
  • Celgene.
  • AbbVie Inc.
  • Johnson & Johnson Services, Inc.
  • Pfizer Inc.

Source: Fortune Business Insights™

With thanks to the Psoriasis Association.

Psoriasis Association | NHS.UK | | Leo Pharma
Capon, F. The Genetic Basis of Psoriasis, International Journal of Molecular Sciences | British Skin Foundation The Psoriasis and Psoriatic Arthritis Alliance | | NICE, Psoriasis: Assessment and Management| Fortune Business Insights