Recently I’ve seen a few patients who have developed allergy-type symptoms – eg hives, itching, racing heart – even though they’ve never had allergies before. They also couldn’t attach their symptoms to a particular food, or to something they had come in contact with.

These people had histamine intolerance.

What is histamine Intolerance?

Histamine intolerance is when a person is unable to break down histamine effectively. Histamine is a naturally occurring chemical that has many important functions in the body. It is also present in some foods, and can be produced by the bacteria in our gut.

Symptoms of histamine intolerance include:

  • Pruritus (itching especially of the skin, eyes, ears, and nose)
  • Urticaria (hives) (sometimes diagnosed as “idiopathic urticaria”)
  • Tissue swelling (angioedema) especially of facial and oral tissues and sometimes the throat, the latter causing the feeling of “throat tightening” (sometimes diagnosed as “idiopathic angioedema”)
  • Hypotension (drop in blood pressure)
  • Tachycardia (increased pulse rate, “heart racing”)
  • Symptoms resembling an anxiety or panic attack
  • Chest pain
  • Nasal congestion and runny nose
  • Conjunctivitis (irritated, watery, reddened eyes)
  • Some types of headaches that differ from those of migraine
  • Fatigue, confusion, irritability
  • Very occasionally loss of consciousness usually lasting for only one or two seconds
  • Digestive tract upset, especially heartburn, “indigestion”, and reflux

More information:

Here is a link to a great article on histamine intolerance by Dr Janice Joneja.