Psoriasis

Overview

Psoriasis is a relapsing inflammatory and scaly skin condition that can first appear at any age. It is caused by genetic and environmental factors. Many sufferers only have a limited number of stable red scaly patches but the disease is occasionally more widespread or more serious such as pustular psoriasis or erythrodermic psoriasis. Moderate to severe psoriasis is potentially a serious illness since it is associated with increased mortality, particularly from cardiovascular disease due to associated obesity and metabolic syndrome. Psoriasis visible on exposed skin can also significantly impact on quality of life including self-esteem, social interactions or career prospects. Arthritis affects about 10% of psoriasis patients and can be a debilitating problem in some patients.

The available treatment modalities for psoriasis are diverse and may include topical creams, phototherapy, oral medications or injectable biological agents. Consultation with a dermatologist at our clinic is advised for individuals with moderate to severe psoriasis or psoriasis not responding adequately to treatment as we can advise and have access to the full range of treatments for psoriasis.

What cause psoriasis?

Genetic factors certainly play an important role, especially in individuals developing psoriasis at an earlier age. A number of genes are likely to be involved and the mode of inheritance is not precisely known but is likely to be complex. However environmental factors are well-documented to contribute. Evidently psoriasis may only affect one of the identical twins highlighting the role of environmental factors in its causation.

The following factors have been documented to precipitate the onset of psoriasis in predisposed individuals

  • Medications: lithium, beta-blockers, some antimalarials and some NSAIDs (non-steroidal anti-inflammatory drugs)
  • Infections: streptococcal throat infection and tonsillitis, and HIV
  • Significant psychological stress
  • Physical trauma or surgery
Lifestyle factors
  • Psychological stress can precipitate the onset of psoriasis or making existing psoriasis worse. Moderate to severe psoriasis is also a cause of depression and anxiety
  • Smoking is a known exacerbating factor for psoriasis, particularly the localized pustular psoriasis on the palms and soles
  • Alcohol excess is common amongst patients with moderate to severe psoriasis. It also makes treatment more difficult as alcohol can interact with medications
  • Sun exposure usually makes psoriasis better. However, this must be done correctly to minimize the risk of sun damage and skin cancers. A small proportion of patients may notice worsening of psoriasis with sun exposure
  • Obesity increases the risk of developing psoriasis in predisposed individuals. It can also worsen existing psoriasis and/or make psoriasis more difficult to treat
How does psoriasis manifest?

Psoriasis may appear for the first time at any age. Disease onset occurs prior to 30 years of age in the majority of patients. However, a small proportion of patients develop psoriasis in their late 50s and 60s.

The great majority of patients have plaque psoriasis. There may be one or many of well-demarcated scaly and red plaques that have a predilection to be on the elbows, knees and scalp. Plaques can be quite thick on the palms and soles leading to cracks and pain. There may also be red patches affecting the flexures (armpits, groins), anogenital area and umbilicus (belly button).

In guttate psoriasis, patients develop an eruption like a ‘shower’ of small plaques on the trunk and limbs. This form of psoriasis is commonly associated with streptococcal throat infection or tonsillitis. Erythrodermic and generalized pustular psoriasis are the most severe forms of psoriasis that must be attended to timely as the patient’s health can deteriorate quickly.

The nails are commonly affected with pits and slight lifting of the nails. Occasionally involvement is severe causing thickening or destruction of the nail unit.

Psoriasis may be difficult to recognize in children as it may have less typical features. It may only affect the nappy area in infants and toddlers. Scalp involvement is common in older children however psoriasis also may only affect one finger or an eyelid.

Complications of psoriasis

Psoriasis is an inflammatory condition that has the potential to affect many other organ systems apart from the skin

  • Psoriatic arthritis occurs in about 10% of all psoriasis patients but can affect up to 40% of patients with moderate to severe psoriasis. Rarely a very destructive form of arthritis can cause severe deformity of the joints. Features of psoriatic arthritis include
    • Morning stiffness in the joints or back
    • Pain and swelling in joints, especially the fingers. It may only affect one finger
    • Pain in the tendons and fascias such as at the heels or in the feet
  • Metabolic syndrome
    Features of this syndrome include obesity, high cholesterol and lipids, and insulin resistance or diabetes. It is a significant cause of death, particularly due to cardiovascular disease. There is increasing evidence that effective treatment of psoriasis improves this metabolic syndrome. Treatment of this metabolic syndrome through weight reduction, dietary measures and exercise also improves psoriasis and makes psoriasis more responsive to treatment.
  • Liver disease
    Liver abnormalities are common in patients with more severe psoriasis. They are often made worse by obesity and excessive alcohol consumption.
  • Psychological complications
    Anxiety, low self-esteem and depression are common and can contribute to alcohol abuse. Increased rate of suicide is observed in psoriasis patients especially in younger patients

 

General skin care for psoriasis
  • Gentle cleansing and application of moisturizers
  • Particular attention to flexures and skin folds if these areas are affected as they can become macerated
  • Minimize trauma or injury to the skin as psoriasis is worse at these sites
Treatment for psoriasis

There is no permanent cure available for psoriasis at the present time. However, there are effective treatments for this condition such that it should cause minimal impact on quality of life. Treatment must be optimized to your own circumstances and also depends on the severity of your psoriasis. Detailed and tailored treatment can only be planned following a formal consultation. Some of the medications can only prescribed by dermatologists. Your treatment may require one or a combination of the following

Topical treatments
  • Tar and tar-based products
  • Corticosteroids
  • Calcipitriol
  • Tazarotene
  • Pimecrolimus or tacrolimus
  • Dithranol
Oral medications
  • Acitretin
  • Cyclosporin
  • Methotrexate
Phototherapy
  • Narrow-band UVB
  • PUVA
Biologics
  • Adalimumab
  • Apremilast
  • Etanercept
  • Infliximab
  • Ixekizumab
  • Secukinumab
  • Ustekinumab