Psoriasis is a prevalent, chronic inflammatory skin disease. Psoriasis is an autoimmune disease, meaning that body's own immune system attacks and damages its own cells for unknown reasons. The lesions are usually non-pruritic, papule-like, and scaly. They spread symmetrically and usually occur on the skin of the elbow, knee, scalp, and behind the ear.

There is a great deal of clinical variation in this disease, including erythrodermic, reverse, guttate, pustular, and plaque psoriasis. Plaque psoriasis is the most common type, characterized by red areas with a silver and white coating of dead skin cells. Psoriasis can also affect the nails and mucous membranes. Psoriasis is associated with psoriatic arthritis in 5% of patients. The disease occurs when the body's immune system sends the wrong signals to speed up the growth cycle of skin cells and their shedding.


Types of psoriasis

Psoriasis vulgaris or plaque psoriasis: This type of disease is the most common type of psoriasis. In this disease, red and dry spots are seen on the skin, gradually turning into silver scaly lesions as they get bigger. Sometimes after the healing of dryness, blood stains can be seen in the cell layers. Skin lesions may be painful or itchy. They also vary in number throughout the body and appear in any part of the body, even within the genitals and soft tissues of the mouth.

Nail psoriasis: This disease appears in a small part of the fingernail or toenail. Under these conditions, nail growth becomes abnormal and the nail changes color, and in acute cases, the nail thickens and loses its shape.

Guttate psoriasis: This type primarily appears in adolescents and children and its main cause is a bacterial infection such as “strep throat”. As a result of this infection, dry patches of skin form on all over the body which often disappear after a while. Small, drop-shaped, scaling lesions appear on the body, hands, feet, and scalp. The lesions are covered by a thin crust and are not as thick as plaques.

Inverse psoriasis: It occurs in areas of the skin that are full of wrinkles. Red, smooth, itchy plaques appear on the folds of skin in areas such as the armpits, groin, buttocks, under the breasts, and around the genitals. Inflamed skin in this area worsens with friction and sweating. Fungal infections are one of the causes of this type of psoriasis.

Scalp psoriasis: If psoriasis develops on the scalp, it can also lead to lesions on the face, ears, and hairline. Therefore, in this case, consequences such as the spread of psoriasis and hair loss are not far from the mind.

Pustular psoriasis: This is a rare form of psoriasis in which very severe inflammation occurs in widespread patches or even in smaller areas on the palms of the hands, the soles of the feet, or the fingers. In this type, in addition to skin lesions, pustules that contain fluid, or pus, may also appear on the skin. Fever, chills, severe itching, and diarrhea are common in this type of disease.

Erythrodermic psoriasis: This disease is less likely to occur; however, it can cover your entire body with red flakes that can itch or burn intensely.

Psoriatic arthritis: In addition to inflammation and flaking of the skin, this disease causes swelling and pain in the joints. Sometimes joint pain is the only symptom and sometimes it is accompanied by a change in the appearance of the nails. Symptoms of Psoriatic arthritis range from moderate to severe and can affect any joint in the body. It can also cause stiffness and severe joint damage and in chronic conditions lead to permanent joint deformity.


What are the symptoms of psoriasis?

  • Red patches of skin with thick silvery scales.
  • Small scaly spots (usually in children)
  • Dry and cracked skin with the possibility of bleeding
  • Itching, burning and pain
  • Thick, cracked or broken nails
  • Swollen and stiff joints

The red patches can affect the entire body skin or just a few small points.


Topical treatments

Topical treatments can be summarized as follows:

  • Corticosteroids
  • Calcipotriene (vit D)
  • Tazarotene
  • Coal tar
  • Anthralin
  • Salicylic acid


Optical treatments (phototherapy)

  • Psoralen plus ultraviolet A (PUVA)
  • Ultraviolet B
  • Narrow-band ultraviolet B 311 nm
  • 308 nm excimer laser


Systemic therapies

  • Methotrexate
  • Retinoid, Acitretin
  • Cyclosporine
  • Biologic therapies such as alpha-sept, etanercept, efalizumab and infliximab.

These new forms of immunomodulatory therapy exert anti-inflammatory effects by acting on molecular targets in the inflammatory pathway of T cells.