Antihistamines are commonly used to treat eczema - the rationale being that eczema is sometimes the result of the body's overproduction or release of histamine as a natural response to allergens. However, antihistamines interfere with the vital role of histamine in the body and also cause side effects that may be worse than the skin condition you're trying to treat. Your best bet is to try an effective, topical eczema treatment that will not alter natural function and will not exacerbate the condition, and to find out the consequences of antihistamines before you choose them as an option.

Histamine is present in almost every cell of the body. Its highest concentrations are in the lungs, skin and gastrointestinal tract. It performs a number of basic functions including the secretion of stomach acids during digestion and regulation of sexual response. It is also a neurotransmitter - a chemical that enables messages to travel from one nerve cell to another.

Histamine's function in the immune system is to increase the blood supply to an area of injury or invasion by a foreign substance so that the body may heal or combat damage with the nutrients and other healing elements in the blood. This action often causes redness, swelling, itchiness, rashes and hives-like skin reactions - which is why antihistamines are often prescribed as eczema treatment.

However, antihistamines are not always safe. Doctors advise that you check with them before taking antihistamines if you have asthma or chronic bronchitis, high blood pressure, glaucoma, problems with your liver, kidney, prostrate or stomach, if you're pregnant or breastfeeding, if you have any other chronic illness or are on any medications including herbal supplements - not exactly an eczema treatment you can just whip out of the medicine cabinet at a moment's notice.

Additionally, taking antihistamines can cause histamine deficiency, the symptoms of which include mouth ulcers, headaches, excessive growth of body hair, ringing in the ears and visual and aural abnormalities. Histamine deficiency is also associated with a number of mental and emotional conditions: studies have found that about half the people diagnosed with schizophrenia have low blood histamine levels. In fact, their condition improved when histamine levels were increased.

If your eczema is accompanied by life-threatening symptoms such as difficulty breathing, you should check with your doctor regarding taking antihistamines. However, if you are simply trying to handle itchy, dry skin, or eczema, use a topical eczema treatment that will not cause further problems.