To begin with, even today, the cause of psoriasis is not known, though certain reasons are being hypothecated.
Though scientific belief indicates that there is a strong genetic component as its main cause, the exact reason why psoriasis occurs is not yet known. How you get psoriasis, therefore, is still a mystery today.
And it is not yet confirmed that genetic factors alone are responsible for psoriasis. And although you may have a strong family history of psoriasis, it does not definitely mean that you will get psoriasis.
If you read the psoriasis statistics you will get an idea, of which type of people are more prone to psoriasis.
Cause of psoriasis
Since the exact cause of psoriasis is not known, there are two hypotheses, which prevail in its development.
- Psoriasis and skin. The first hypothesis sees psoriasis primarily as a disorder of the skin cells, which grow very rapidly and migrate to the skin surface to form a slough of dead cells that form the scales on the skin so typical of psoriasis.
- Psoriasis and the immune system. The second and more recent hypothesis sees psoriasis as a disorder of the immune system and the excessive production of skin cells as secondary to this. This hypothesis is supported by the fact that psoriasis responds to medication that suppresses immunity.
In 1979, researchers accidentally discovered that immunosuppressant therapy that was being given for bone transplant also freed the patient of his psoriasis symptoms.
The white blood cells form an important part of the immune system. The T lymphocyte or the T cell is a type of white blood cell, which plays a key role. It is the T cells, which travel throughout the body to detect and neutralize any foreign invasion of the body by bacteria or viruses.
Due to a defect in the immune system, as in psoriasis, the T cells attack the healthy skin cells, mistaking them for foreign substances.
There is a greater activity of the T cells, which migrate in greater numbers to the dermis of the skin. This triggers off the release of cytokines, which cause the skin cells to multiply and proliferate rapidly.
Inflammation is also seen as a result of this autoimmune activity. Inflammation results in increased dilation of the blood vessels and an increased number of WBCs in the outer layer of the skin.
There is, therefore, larger production of skin cells, which rapidly migrate to the outer layer of the epidermis. What causes this malfunction of the immune system is not yet known. This cycle continues until treatment stops it.
(Cytokines, referred to above, are proteins, manufactured by the white blood cells, and which act as messengers to the nervous system to help activate the immune system in case of an attack by alien agents such as bacteria or viruses).
Factors that can trigger psoriasis and its flare-ups
As mentioned above, the exact cause of psoriasis is not known, but there are certain factors that can trigger its onset.
Many people who may be prone and have remained free of symptoms for a long time, can develop psoriasis when exposed to certain factors that trigger this condition.
These factors can also cause existing psoriasis to flare up.
Such psoriasis triggers include:
- Infections such as streptococcal throat infection or thrush
- Stress and anxiety can trigger an onset or make an existing psoriasis worse.
- Cold weather
- Heavy consumption of alcohol
- Dry skin
- Severe sunburn
- Cut in the skin or a bug bite. This can cause psoriasis patches anywhere on the skin and not necessarily at the injury site.
- Injury to the nails
- Certain medicines can also trigger psoriasis. They include:
- Beta-blockers that are given for high blood pressure.
- NSAIDs.(nonsteroidal anti-inflammatory drugs)
- Lithium prescribed for bipolar disorder
Risk factors that make you prone
Besides the triggers, there are some psoriasis risk factors that can make you prone to develop psoriasis..
- Genetics. Genetically prone people or people with a family history of psoriasis are more likely to get psoriasis. According to The Psoriasis and Psoriatic Arthritis Alliance, If both parents have psoriasis then the risk of their children developing psoriasis is 75%, and if one parent has psoriasis, the risk of children developing the disease is 15%.
- Recurrent bacterial infection. Children and young adults with recurring infections, particularly strep infection of the throat are very prone to psoriasis.
- Compromised immunity as in HIV. People with a compromised immune system as in HIV infection are more likely to develop psoriasis.
- Obesity. Obesity makes an obese person prone to psoriasis because of lowered immunity. How or why immunity drops because of obesity is still not known, but scientists do maintain that obese people show a higher tendency to catch infections. Obesity does harm the immune system and the immune cells do not show the same efficacy to fight infection as in a person with normal weight.
- Stress. A person who is under constant mental stress and anxiety becomes a potential candidate for psoriasis. This again is because stress, off and on, can adversely affect your immunity. And to make matters worse, a psoriatic patient develops increased stress because of the stigma and pain associated with this disease. Learning to handle stress, therefore, becomes important if you have psoriasis.
- Smoking. Smokers have twice the risk of developing psoriasis as compared to non-smokers. Those who smoked about 20 cigarettes or more are 5 times more likely to develop this disease. The severity of psoriasis is also more among smokers than non-smokers.
- Alcohol. Alcoholic beverages such as beer, champagne, and alcoholic hard drinks make you a more likely candidate for developing psoriasis. The prevalence of psoriasis is 5% among alcoholics as compared to 1% among those who do not consume alcohol. The form of psoriasis is also more severe accompanied by intense itching. Alcohol abuse also limits the chances of the success of psoriasis treatment. Alcoholics are, therefore, more prone to develop complications.