What is psoriasis?

Psoriasis is a chronic, immune-mediated inflammatory skin disease that causes skin cells to grow much faster than normal, leading to thick, scaly plaques on the skin. It is not contagious and typically follows a relapsing-remitting course, with periods of flares and improvement.

 

What are the causes?

The exact cause of psoriasis is not fully understood, but it is considered to be a multifactorial disease with immune-mediated and genetic factors playing a role.

 

 

What are the triggering factors?

●      Infections (e.g., Streptococcus throat infection)

●      Certain drugs (e.g., β-blockers, lithium)

●      Physical trauma to the skin (Koebner phenomenon)

●      High stress levels

●      Cold and dry weather

●      Smoking or alcohol use

●      Obesity

What are the common types of psoriasis?

The main types of psoriasis include:

●      Plaque psoriasis (the most common type, accounting for about 80–90% of cases)

●      Guttate psoriasis

●      Inverse (flexural) psoriasis

●      Pustular psoriasis

●      Erythrodermic psoriasis

 

 

What is plaque psoriasis?

Plaque psoriasis is the most common form of psoriasis, characterized by sharply defined, erythematous plaques covered with silvery-white scales.

 

 

What are the clinical features of plaque psoriasis?

●      Symmetrically distributed, well demarcated erythematous plaques covered with silvery-white scales

●      The most common sites are the extensor surfaces (elbows, knees), scalp, and lower back

●      Auspitz sign which is a pinpoint bleeding after removal of scales

●      May be associated with psoriatic arthritis (joint pain and stiffness)

●      Nail involvement may occur

 

 

What are the treatment options?

 

General measures

-        Emollient

-        Avoid triggers such as stop smoking

Mild disease

-        Topical corticosteroids

-        Topical vitamin D analogs (calcipotriol)

-        Topical calcineurin inhibitors

Moderate to severe disease

-        Phototherapy: narrowband UVB, PUVA, or excimer laser

-        Systemic agents: methotrexate, cyclosporine, or acitretin

-        Biologic therapy: TNF-α inhibitors, IL-17 inhibitors, IL-23 inhibitors, or IL-12/23 inhibitors

 

Scientific Content: Dr. Omniyyah Hawsawi

Reference: DermNet