Recently, we have dedicated a day for 'psoriasis' as well... not many are aware of what psoriasis is and why this skin disease causes a hurdle in our peace… try to have an idea;

Researchers have found 9 gene mutations that may be involved in causing psoriasis. One of these mutations on chromosome 6, called PSORS-1, appears to be a major factor that can lead to psoriasis. Mutations on genes cause certain cells to function differently. With psoriasis, these mutations seem to largely affect T-helper cells.

Immune System Causes of Psoriasis

In a normally functioning immune system, white blood cells produce antibodies to foreign invaders such as bacteria and viruses. These white blood cells also produce chemicals that aid in healing and fighting infective agents. But with psoriasis, special white blood cells called T-cells become overactive.

These T-cells "attack" the skin and set off a cascade of events that make the skin cells multiply so fast they start to stack up on the surface of the skin. Normal skin cells form, mature, then are sloughed off every 30 days. But in plaque psoriasis the skin goes through this whole process in 3-6 days.

Normally T-cells produce chemicals that help heal the skin. In psoriasis, T-cells produce an abnormally large amount of these chemicals and actually cause more inflammation in the skin and joints.

Environmental Causes of Psoriasis
Not everyone who has these gene mutations gets psoriasis and there are several forms of psoriasis that people can develop. Certain environmental triggers play a role in causing psoriasis in people who have these gene mutations.

Skin Injury
Sometimes an injury to the skin can cause the formation of a psoriasis patch. This is known as the Koebner Phenomenon, and it can occur in other skin diseases, such as eczema and lichen planus. It can take 2 to 6 weeks for a psoriasis lesion to develop after an injury. Types of injuries that can trigger a flare include:

Abrasion-even mild abrasion
Increased friction from clothing or skin rubbing against skin in folds, such as armpits or under breasts

Sunburn
Viral rashes
Drug rashes
Weather

Weather is a strong factor in triggering psoriasis. Exposure to direct sunlight, which usually occurs in the warmer months, often improves the rash. On the other hand, cold, short days seen in the winter months can trigger the rash to worsen.
Stress

Psychological stress has long been understood as a trigger for psoriasis flares, but scientists are still unclear about exactly how this occurs. Studies do show that not only can a sudden, stressful event trigger a rash to worsen, daily hassles of life can also trigger a flare. In addition, one study showed that people who were categorized as "high worriers" were almost two times less likely to respond to treatment compared to "low worriers."

Infection
Infections caused by bacteria or viruses can cause a psoriasis flare. Streptococcal infections that cause tonsillitis, or strep throat, tooth abscesses, cellulitis, and impetigo can cause a flare of guttate psoriasis in children. The human immunodeficiency virus (HIV) does not increase the frequency of psoriasis, but it does increase the severity of the disease.

Low Vitamins
Low levels of calcium have been reported as a trigger for psoriasis. Oddly enough, even though medications made from vitamin D are used to treat psoriasis, low levels of vitamin D do not trigger a flare-up.