Histamine is a substance found in the tissues of nearly all plants and animals, and is based on the molecular structure of ammonia. It is the product of a natural process that removes carbon, oxygen and/or hydrogen atom compounds from the amino acid histidine. In humans, histamine is most commonly known for its role in allergic reactions, but it also is associated with other roles in the body, such as sleep regulation, digestion, immunity and sexual function. When humans have an allergic reaction, high levels of histamine are released from body tissues to help fight infection. High histamine levels could be a temporary condition, such as in an allergic response, or a chronic condition caused by disease or congenital factors.
Temporarily high histamine levels that stem from allergic reactions can be induced by a wide range of stimulants, from pollen to cat hair to fermented food. Symptoms can include sneezing, watery eyes, runny nose, hives, nausea and diarrhea. Treatment generally revolves around alleviating symptoms and removing the source of irritation until the histamine levels and other body functions return to normal. Non-prescription medications such as antihistamines, which block the body’s receptors to histamine, are commonly used.
Chronic conditions that cause high histamine levels include mastocytosis and various autoimmune disorders. Treatments vary with the condition. They can include the use of epinephrine, mast cell stablizers, corticosteroids, antihistimines and other theraputic approaches.
"Histadelia" is a term that was coined by Carl Pfeiffer, a biochemist, to describe high histamine levels in relation to certain mental illnesses, such as schizophrenia. Even though high histamine levels and correlating symptoms are commonly acknowledged in the medical industry, histadelia is not a universally accepted condition, term or classification. Proponents of histadelia cite that it is more prevalent in males, and up to 20 percent of schizophrenics have high histamine levels. Symptoms of histadelia include low levels of serotonin and dopamine, elevated basophils, obsessive-compulsive-disorder tendencies, delusional thinking and sparse body hair. Treatment of Histadelia is said to take as long as 12 months, and it includes biomedical care that involves nutrient replacement.