Plaque psoriasis epidemiology

Psoriasis is a chronic, inflammatory and relapsing skin disorder that has a strong genetic basis and plaque psoriasis is one form of psoriasis. It results from the interaction between multiple genetic as well as environmental factors.

plaque psoriasis

The T-cells in the body are induced to produce cytokines which then stimulate keratinocyte proliferation thus the production of dermal antigenic adhesion molecules in blood cells.

Epidemiology

  • Both men and women are equally affected by psoriasis.
  • Plaque psoriasis accounts for nearly 90% of all people suffering from psoriasis
  • It occurs at any age but the majority of cases first show signs before the age of 35 and it’s uncommon in children.
  • Joint disease is usually associated with psoriasis
  • Risk factors
  • Alcohol and smoking
  • Trauma (it may spread to various to uninvolved areas when the patient suffers
    chronic plaque psoriasis
    from certain types of trauma)
  • Hormonal changes (post partum)
  • There is usually a multi-factorial pattern of inheritance
  • Psychological stress
  • Environmental factors. There are certain things that can trigger or aggravate plaque psoriasis including: sunlight (normally, patients notice a decrease in severity when exposed to sunlight for long periods and it worsens during winter) and infections. Some of the infections include: streptococcal infections which are strongly associated with guttate psoriasis and HIV infections and AIDS.
  • Drugs which include; Imiquimod, lithium, some antibiotics, Gemfibrozil, trazodone, anti–malarials, terfenadine, sudden withdrawal from systemic steroids, Beta-adrenoreceptor blocking drugs, angiotensin converting enzyme inhibitors (ACE) and non-steroidal anti-inflammatory drugs.

Associated diseases

Some of the diseases associated with chronic plaque psoriasis include;

  • Inflammatory bowel disease
  • Metabolic syndrome (an abdominal obesity, insulin resistance, hypertension and dislipidaemia)
  • Psoriatic arthritis
  • People suffering from psoriasis have an increased risk of cardiovascular disease

Presentation

chronic plaque psoriasisSome of the symptoms seen in people suffering from chronic plaque psoriasis include itchy and well demarcated ovular bright red elevated lesions which have an overlying silvery or white scale. These plaques are symmetrically distributed over the body and the scalp. Assessments carried out on patients with psoriasis show the disease’s severity and its impact on the psychological, physical and social well-being of the patient. Severe episodes of plaque psoriasis may transform into more severe forms of the disease for instance erythrodermic or pustular psoriasis. So what are the common symptoms associates with this form of psoriasis?

  • Patients experience fissuring within the plaques when lesions are present over the joint lines or on the soles and palms.
  • The lesions normally have a distinctive full, rich red color. However, when on the legs, they sometimes have a violaceous or blue tint.
  • The plaques sometimes appear to be immediately encircled by a paler peripheral zone.
  • Vigorous scraping of the scales causes pinpoint bleeding while gentle scrapping accentuates the scales.
  • New lesions tend to appear at sites of trauma or injury (typically within 1-2 weeks after the trauma)
  • Nail changes occur with subungual hyperkeratosis, onycholysis, pitting, onycholysis, subungual hyperkeratosis or yellow-red discoloration of the nails.Plaque psoriasis the example
  • Plaque psoriasis shows slightly different symptoms in kids. The plaques aren’t as thick and the lesions are less scaly. It affects the face more in children than it does adults and it often appears in the nappy and flexural region when they are still in infancy.

Assessment of its severity

The durations and extent of chronic plaque psoriasis varies greatly. The lesions also vary in size and typically range from one to several centimeters. The numbers of lesions that occur also vary from patient to patient and the smaller plaques may join to form larger lesions. This occurs especially on the sacral and leg regions.

When you are assessing the severity of the disease, you should take note o the following;

  • Surface area of the body affected
  • The conclusions of a static physician global assessment (this is a 6 point scale measuring the overall disease severity at the time of assessment as clear, nearly clear, moderate, mild, very severe or severe)
  • Involvement of the nails, hard to treat areas like genitals, flexurals, soles, palms and the scalp, and high impact.
  • The patient’s own of the disease’s severity based on the static ant’s global assessment
  • · Systemic upsets such as malaise and fever which are common in unstable forms of the disease like generalized pustular psoriasis or erythroderma psoriasis.

When it affects <5% of the body’s surface area, the psoriasis is classified as mild, when it affects 5-10% of the body’s surface area, it is classified as moderate and when it affects >10% of the body’s surface area, it is classified as severe. To express the disease’s severity you can make use of tools like the Psoriasis Area and Severity Index (PASI). This way you can assess its severity based on the severity of the lesions and extent to which the skin is affected.

Differential diagnosis

psoriasis

  • Superficial basal cell carcinoma
  • Syphilis
  • Bowen’s disease
  • Lichen planus
  • Dermatitis
  • Tinea corporis
  • Drug eruptions
  • Pityriasis rosea
  • Discoid lupus erythematosus
  • Seborrhoeic dermatitis
  • Cutaneous T-cell lymphoma (considerations where rashes aren’t responding to optimal forms of treatment of there is color variation between the plaques)

Investigations

Diagnosis is made based on clinical findings and skin biopsies are rarely required to confirm the diagnosis.

Management

Management options for the treatment of plaque psoriasis include;

  • First line therapy which involves traditional topical therapies. For instance vitamin D analogues, corticosteroids, tar and dithranol preparations.
  • Second line therapy which involves phototherapy, narrow band and broad band ultraviolet B light, supervised or without supervision of complex therapies like crude coal tar, dithranol in Lassar’s paste and non-biological systemic agents like methotrexate, acitretin and ciclosporin.
  • Third line therapy which is the systemic biological therapies that uses molecules designed to block some molecular steps which are crucial to the development of psoriasis. These steps include the stopping the TNF antagonists etanercept, adalimumab, ustekinumab and infliximab.

There is still no evidence that any of these interventions have an impact or a disease modifying effect beyond improvement of the psoriasis. However, those who are afflicted by chronic plaque psoriasis should take all the necessary measures to ensure that they do not aggravate the disease. Some even more serious forms of psoriasis pose a risk to lives of the patients and its better not to risk your life in the first place. Sometimes, other diseases pose similar symptoms to psoriasis so make sure you get a diagnosis from a qualified doctor.

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