was ist histamin — what symptoms are typical?

Histamine is a biogenic amine that acts as a signaling molecule in the body, involved in allergic reactions, inflammation, and gastric acid secretion. It is stored in mast cells and basophils and released upon allergen exposure. Typical symptoms of histamine release or intolerance include sneezing, runny nose, itchy skin, hives, headaches, diarrhea, nausea, palpitations, and blood pressure fluctuations. In histamine intolerance (DAO deficiency), symptoms may also occur after consuming histamine-rich foods like aged cheese, wine, or sauerkraut. The provided contexts contain no specific information on histamine; this answer is based on well-established medical knowledge. Note: Persistent symptoms require medical evaluation to rule out other causes.