What Is Chronic Plaque Psoriasis?

The majority of plaque psoriasis cases are classified as large or small plaque psoriasis. Plaques might be localized such as to the elbows and knees or widespread involving the scalp, trunk, and limbs. 

Large plaque psoriasis

• Lesions are thicker and usually broader, with more defined margins in large plaque psoriasis than in small plaque psoriasis. Crusty sections are red and have a whitish-silvery scale.
• Large plaque psoriasis can appear at any age; however, it is more common in people younger than 40 years. According to several research, the condition is linked to metabolic syndrome. Metabolic syndrome is characterized by the presence of obesity, high cholesterol, high blood sugar, and high blood pressure, and it tends to run in families. It can be more difficult to cure than small plaque psoriasis because it is resistant to treatment.

Small plaque psoriasis

• This form of psoriasis creates plenty of little lesions, each no more than a few millimeters or centimeters in diameter. They might either stay separate or combine. Crusty areas on top are pink, with fine scales and a thinner crust in small plaque psoriasis than in large plaque psoriasis.
• A psoriasis family history is less prevalent in this form of the disease. Lesions may be well defined or blend with the skin. It is less common to have a family history. 
• Although it can occur at any age, small plaque psoriasis is most common in people older than 40 years. Phototherapy is generally effective in treating this type of psoriasis.

Chronic stable plaque psoriasis

This is the most common type of plaque psoriasis and psoriasis in general. Lesions often remain or reappear after the first outbreak. The elbows, knees, chest, and head and scalp are the most commonly affected locations, but there may be others.

Plaques usually appear on both sides of the body. For example, if they emerge on one elbow, they will also appear on the other.

Seven uncommon subtypes of chronic plaque psoriasis include:

1. Rupioid psoriasis: Characterized by limpet-like cone-shaped hyperkeratotic psoriasis lesions.
2. Lichenified psoriasis: The area around the lesions of psoriasis is thickened due to persistent rubbing or scratching.
3. Elephantine psoriasis: Characterized by chronic, densely scaled psoriasis in large regions.
4. Ostraceous psoriasis: Characterized by densely scaled, ring-like psoriasis that resembles an oyster shell.
5. Linear psoriasis: Psoriasis that runs down the body in lines (often corresponding to fetal developmental lines).
6. Koebnerised psoriasis: Psoriasis that develops in a region of skin trauma such as an injury, infection, surgical wound, or scratch mark.
7. Photosensitive psoriasis: Photosensitive psoriasis occurs when psoriasis flares up in sun-exposed regions such as the face, neck, hands, and forearms. Most patients with psoriasis feel that ultraviolet light is really beneficial to their condition. Following sun exposure, a small percentage of people develop rash exacerbations. Clear sunburn lines may be visible in some people. They might possibly have plaque psoriasis elsewhere. Strict sun protection is essential, along with other treatments, to control this type of psoriasis.

Various risk factors for chronic plaque psoriasis include:

Hereditary

Psoriasis appears to be inherited. One in every three people with psoriasis has a first-degree relative with psoriasis. About 10 percent of people are born with genes that predispose them to psoriasis. However, only approximately three percent of people develop the condition. Nonetheless, if both parents have psoriasis, a kid has a 50 percent risk of acquiring the condition.

Triggers

Seven triggers that exacerbate or relapse psoriasis include:

1. Sun exposure (In general, prolonged exposure to sunlight reduces the severity of psoriasis. However, some people who are sensitive to sunlight can get a sunburn, which exacerbates plaque psoriasis.)
2. Infections (Streptococcal infections are strongly associated with the development of chronic plaque psoriasis.)
3. Drugs
   • Lithium
   • Antimalarials
   • Withdrawal of systemic steroids
   • Nonsteroidal anti-inflammatory drugs
   • Angiotensin-converting enzyme inhibitors
   • Beta-adrenoreceptor blocking drugs
   • Gemfibrozil
   • Antibiotics such as tetracycline and penicillin
4. Psychological stress
5. Hormonal changes following childbirth (postpartum)
6. Trauma
7. Smoking and alcohol consumption

Chronic plaque psoriasis was found to have an association with other inflammatory diseases apart from psoriatic arthritis, which is developed in 7 to 40 percent of people with psoriasis. This association is found to be stronger in severe forms of psoriasis.

Comorbid conditions include:

1. Cardiovascular disorders (CVD) (Traditional risk factors for CVD such as hypertension, diabetes, obesity, and other metabolic syndromes are high in patients with psoriasis.)
2. Metabolic disorders (disorders such as diabetes and dyslipidemia increase with severe psoriasis)
3. Metabolic syndromes (risk factors such as central obesity, insulin resistance, hypertension, and dyslipidemia increase)
4. Kidney diseases
5. Inflammatory bowel syndrome

Several studies have reported a link between psoriasis and other comorbidities. However, larger studies are to be conducted to confirm this association. Comorbidities include:

• Cancer, particularly T-cell lymphoma
• Mental health conditions
• Pneumopathies, including
  • Chronic pulmonary diseases
  • Obstructive sleep apnea
• Peptic ulcer disease
• Hyperuricemia or gout
• Osteoporosis
• Sexual dysfunction

A dermatologist (skin doctor) can usually identify if the person has plaque psoriasis simply by taking their extensive medical history, asking about other comorbidities and smoking history, and examining their skin thoroughly. 

However, sometimes, it can be difficult to diagnose because psoriasis can resemble eczema and other skin conditions. The doctor may perform a biopsy in some circumstances. They will collect a microscopic sample from the skin and examine the cells under a microscope.

There is no definitive treatment for psoriasis, and people with chronic plaque psoriasis often experience the condition for the rest of their lives. The goal of the treatment is to enhance the patient's quality of life by lowering plaque size, scaling, and thickness. Some people with moderate psoriasis may opt not to get therapy, and some will experience spontaneous clearance of plaques without treatment.

Medical treatment

Approximately, 80 percent of patients with chronic plaque psoriasis be treated in primary care using topical treatments including corticosteroids and vitamin D analogs for mild cases.

Patients who have more than 20 percent of their body surface area affected should be referred to a higher care center because topical therapies alone may not provide enough relief in such cases.

For moderate to severe conditions, treatment is done with:

• Phototherapy, which comprises
  • Narrow-band ultraviolet B light
  • Photochemotherapy
• Systemic medicines such as
  • Cyclosporine
  • Methotrexate
  • Acitretin 

If these treatments fail, patients are treated with biological medicines such as TNF-antagonists such as adalimumab, etanercept, infliximab, or the anti-IL12/23 monoclonal antibody ustekinumab. 

Lifestyle modifications

Smoking, alcohol consumption, and obesity have all been linked to the development of psoriasis and worsening of symptoms. Although enough clinical studies have not been conducted, it is believed that lifestyle adjustments such as weight reduction, reduced alcohol use, or smoking cessation may improve symptoms.

Psoriasis has a chronic-relapsing course that needs long-term treatment. Relapse should not be considered a treatment failure. The frequency of relapse and its effect on the quality of life should be considered when considering treatment modification.

A meta-analysis found that 88 percent of patients relapsed within six months after starting topical therapy, with no clear indication that one treatment was more effective than another.