Psoriasis an inflammatory skin condition characterized by frequent episodes of redness, itching, and thick, dry, silvery scales, on the skin. The musculoskeetal system may also be affected with an inflammatory arthritis, which at times may be debilitating.

Psoriasis can appear suddenly or gradually. It may affect any age, most commonly begins between 15 and 35. It occurs most frequently in Caucasians. Psoriasis is characterized by frequent episodes of recurrences and remissions.

The cause of psoriasis is unknown but it seems to be an inherited disorder. It is most commonly seen on the trunk, elbows, knees, scalp, skin folds, or fingernails, but it may affect any or all parts of the skin. Normally, skin takes about a month for its new cells to move from the lower layers of the skin up to the surface. In psoriasis, this process takes only a few days, resulting in build-up of dead skin cells and formation of thick scales.

Psoriasis may be aggravated by injury or irritation (cuts, burns, rash, insect bites), and it may be severe in immunosuppressed persons (such as with chemotherapy for cancer, or with AIDS) or those who have autoimmune disorders (rheumatoid arthritis). Medications, viral or bacterial infections, excessive alcohol consumption, obesity, lack of sunlight, overexposure to sunlight (sunburn), stress, general poor health, cold climate, and frequent friction on the skin are also associated with flare-ups of psoriasis. Psoriasis is not contagious.

Additional symptoms that may be associated with this disease include nail abnormalities, genital lesions (male), and eye burning, itching and discharge.

Psoriasis is a chronic, lifelong condition that can be controlled with treatment. It usually does not adversely affect general health, unless it is neglected or occurs at the old or very young age. [Md Shahidullah]