Have you ever read the novel Brave New World (by Aldous Huxley)?  Toward the beginning of the book, the process of human engineering is explained, the main ingredient of which is alcohol — fetuses develop well or not so well based on how much alcohol they are exposed to (deliberately).  I bring this up to illustrate the general fact that alcohol is a poison to our bodies.

It is no surprise, therefore, that alcohol weakens the full grown human body, especially vital elements such as the liver, blood and immune system. The weaker the body is, the more susceptible it will be to psoriasis flare ups.

It has been observed that people suffering from psoriasis tend to drink more than those without, which then makes the condition worsen.  On the other hand, people who abstain from alcohol altogether tend to see noticeable (sometimes dramatic) improvements in their psoriasis.

Alcohol can also hinder psoriasis medications, or cause them to function adversely.  This is also a general rule with all body-altering medications, whether or not it mentions alcohol on the bottle.

Also, alcohol (I hate to admit) is an ineffective method for dealing with stress.  Whereas emotional stress causes wear and tear on the body in one way, alcohol only introduces another kind of physical stress, thus introducing the body to an unhealthy cycle from which it will struggle to recover.  Such patterns steadily weaken the body’s natural defenses, thus opening it up to unbridled psoriasis break-outs.