Hot peppers (Chili peppers) include a special ingredient called Capsaicin in their composition. Capsaicin is the particular ingredient which makes Chili peppers taste hot. Pure Capsaicin is a colorless and odorless crystalline compound.
Some plants naturally have Capsaicin in them for the protection of their leaf from animals eating them, and possibly also for the protection from certain fungi. The highest concentrations of Capsaicin are usually found in the fleshy parts of the seeds and the fruits of the genus Capsicum plants (ie chili peppers, red or green peppers).
Capsaicin causes a sensation of heat anywhere it comes in the contact with the skin (especially in the sensitive skin areas) or the mucous membranes of a human or an animal.
Capsaicin is used in the sprays for the riot control, as it will cause a severe burning if it gets onto the face or into the eyes of a human.
In medicine Capsaicin is most commonly used as a component of the Over the Counter (OTC) pain relievers for arthritis, and sometimes also as a circulatory stimulant. Over the Counter pain relieving creams usually contain Capsaicin in concentrations between 0.025% and 0.075%. Some studies show that Capsaicin can also help to reduce the pains, associated with Psoriatic Arthritis.
Topical creams with Capsaicin help to relieve the pain in the nerve endings near the skin surface. Capsaicin interrupts the action of molecules at the nerve endings, which affect how the brain recognizes pain, itch, and heat. When Capsaicin is removed, the nerve endings recover back to their normal state.
May Capsaicin also help in psoriasis treatment? And if yes, then how will it – topically or internally?
Several double-blind placebo controlled studies have shown that a topical application of a 0.025% cream with Capsaicin has helped to sufficiently relieve the skin symptoms in the people with psoriasis when compared to the placebo controlled group of people with psoriasis.
Due to the burning sensation caused by Capsaicin when it comes in contact with mucous membranes (mucous membranes include mouth, gums, stomach, intestines, nose, bronchial tubes, and urinary tract), it is often used in food products to make them taste spicy or "hot".
According to some studies, Capsaicin may also cause the release of endorphins in the body – the compounds produced by the pituitary gland and the hypothalamus during exercise, a sexual intercourse, an excitement etc. Endorphins cause a feeling of pleasure when released into the human body.
Some people with psoriasis say that they also benefit from the dietary intake of foods containing Capsaicin. Other people can not use Capsaicin as an internal psoriasis treatment, due to that, hot peppers (Chili peppers or Cayenne peppers) and other products with Capsaicin cause heartburn in them.
I suspect that Capsaicin may work in psoriasis treatment due to acting as an irritant for the psoriatic plaques. Just as with Cryotherapy (treatment with the use of ultra low temperatures), Capsaicin may irritate the skin due to causing the sensation of a strong heat on the skin, and thus to cause the skin to "pay attention" to what is going on with the site and to adjust accordingly.
Capsaicin may also serve a natural anti-inflammatory agent for the psoriatic plaques.