Plaque Psoriasis: Causes, Symptoms, and Treatment

Introduction

Plaque psoriasis is the most common immune-mediated inflammatory condition affecting joints and skin and causing abnormalities in other systems. The most common clinical type of psoriasis is plaque psoriasis. About eight to ninety percent of individuals with psoriasis have plaque psoriasis. It is not a life-threatening condition, but treatment is difficult. The condition presents with oval-circular large plaques over the trunk, scalp, and extensor body surface. About 15 percent of those with plaque psoriasis develop psoriatic arthritis. Psoriasis has a global prevalence of one to eight percent. It affects individuals of both sexes. About one-third of the cases have a childhood occurrence.

What Are the Causes?

Psoriasis is a condition that has a multifactorial etiology.

The risk factors that trigger psoriasis are:

• Stress.

• Alcohol.

• Sunlight.

• Smoking.

• Infection.

• Drugs.

• Trauma.

• Sunlight.

Drugs that can exacerbate the condition include calcium channel blockers, beta-blockers, antimalarial, penicillin, lithium, interleukin, etc. Genetic factors also play a role. Individuals with susceptible loci on chromosome 6 are more likely to develop the condition. Different types of trauma are linked with plaque psoriasis. Excessive scratching can aggravate or trigger the condition. When psoriatic plaque develops at the site of trauma, it is called the Koebner reaction. Sunlight is beneficial to some of the affected, while in others, it may aggravate the condition.

What Are the Symptoms?

• Some of the affected are asymptomatic and present with no symptoms.

The affected mostly present with symptoms like:

• Well-defined erythematous plaques are mostly distributed over the knees, lower back, elbows, and scalp region.

• Itching mostly occurs in cases of scalp involvement.

• Fissuring.

• Soreness.

• Pain.

• The number of plaques varies but are symmetrical.

• Auspitz sign (plaques are covered by silvery-white patches that, on removal leaves bleeding spots) present.

• Similar lesions along the line of trauma indicate active disease and are called the Koebner phenomenon.

How Is the Condition Diagnosed?

• The diagnosis of plaque psoriasis is mostly based on clinical evaluation. Well-defined scaly erythematous plaques with symmetrical distribution recognize the condition.

• A biopsy helps in distinguishing plaque psoriasis from other similar inflammatory skin conditions.

• The affected are screened for metabolic comorbidities like diabetes, obesity, hypertension, dyslipidemia, and inflammatory arthritis.

What Are the Treatment Options?

• Topical Application - Includes the use of moisturizers and emollients. Topical steroids are effective in improving plaques. The main side effects associated with topical steroids are striae, skin atrophy, and tachyphylaxis.

• Light Therapy - Light therapy uses ultraviolet light, mostly ultraviolet B. The different therapies include targeted or whole-body therapy, home phototherapy, photochemotherapy, and LASER (light amplification by stimulated emission of radiation).

• Medications - Systemic drugs like tacrolimus, methotrexate, cyclosporine, biologic agents, etc. Of the biological agents available, Ixekizumab, Tildrakizumab, Adalimumab, Infliximab, Secukinumab, etc., are used for plaque psoriasis treatment.

• Vitamin D Derivatives - Vitamin D derivatives inhibit the proliferation of keratinocytes and improve their differentiation. The main side effect is that it causes perilesional skin irritation, which can lead to cessation of treatment.

Special care should be taken while treating pregnant women with plaque psoriasis. Ultraviolet B phototherapy can be safely used in pregnancy. As psoriasis is a chronic condition, recurrence, and emissions are possible; therefore, prolonged therapy is needed. The choice of treatment is made after considering the long-term associated side effects. Those with moderate to severe disease should consult a dermatologist, and those with inflammatory joint disease should consult a rheumatologist.

The practice guidelines include:

• The condition is considered extensive if more than 10 percent of the body surface area is involved.

• In cases of extensive disease, Cyclosporine or Methotrexate is considered.

• Biological therapy should be considered early.

• In the case of women of childbearing age undergoing biological therapy, contraceptive use is recommended.

• For women of childbearing age undergoing light therapy, folate supplementation is required.

• In those receiving ultraviolet therapy, genitals should be protected.

What Are the Complications?

The complications include:

• Constant itching.

• Disfigurement.

• Reduced quality of life.

• Treatment side effects include liver damage, increased susceptibility to infections, and skin cancer.

• Poor aesthetic appearance can lead to isolation, withdrawal from society, and depression.

Psoriasis is also associated with adverse cardiac events and obesity.

What Is the Prognosis?

Plaque psoriasis is an unpredictable disease. It is impossible to accurately predict which individuals will have remissions or how long the disease will last. Moreover, there is no permanent cure. Though the condition is not life-threatening, the recurrences and remissions adversely affect the quality of life of those affected.

Poor prognostic factors include:

• Stress.

• Early symptom onset.

• Familial history.

What Is the Differential Diagnosis?

Psoriasis should be differentiated from:

• Tinea Corporis - It is a superficial skin infection caused by dermatophytes.

• Eczema - A skin disease that results in dry, itchy skin patches. It results in skin irritation and causes dark skin patches. In plaque psoriasis, the patches are silvery or white and rise above the skin.

What Are the Home Remedies?

The home remedies that can help in managing the symptoms of plaque psoriasis are:

• For severe itching, take over-the-counter medications (antihistamines).

• Avoid tight clothing so that the affected area can breathe.

• Use mild soaps that are free of alcohol, dyes, and perfume. Avoid harsh soaps.

• Avoid hot water and use lukewarm water for bathing. Reduce the time spent bathing to less than 15 minutes.

• Frequently moisturize the skin using an ointment or cream.

• Herbal therapies like aloe vera are sometimes effective (suggested by certain studies).

Conclusion

Psoriasis is an immune-mediated disease that causes inflammation in the body. The most common form of psoriasis is plaque psoriasis. Plaque psoriasis is characterized by erythematous plaques that are scaly, silvery, or white. Diagnosis is mostly based on clinical evaluation; in some cases, a biopsy may be needed. The mainstays of topical therapy are topical steroids and vitamin D derivatives. In chronic cases, cases that involve greater than 20 percent of the body area, or cases of unresponsiveness to topical therapy, other options like light therapy or systemic medications are used. Though not life-threatening, the condition can significantly affect one’s quality of life.