Expert: Dr Ian Jackson - please note UK based - 6/10/2008

Question
Hi, I am having hydrocele, would like to perform surgery. But I am very much allergic to sudden climate change, hot bath, heavy exercises and red-ant bites (which releases histamine) because of which I got urticaria and atleast two times in my life my blood pressure fall upto 85/55 with difficulty in breathing. With administration of anti-histamine injection, I recovered slowly within one hour. Would you please suggest me precautions to be taken before anesthesia both general and local. How can I knew that in advance that I am allergic to anesthesia or not. Thanks very much.

Answer
Hi there
Allergy to local anaesthesia is very very rare though it can happen. It's down tot he type of the drug and so it doesn't tend to cause problems.
Inhalational agents in anaesthesia Isoflurane, sevoflurane etc are also very very safe - as they are inhaled rather than injected this seems to confer a major advantage in the prevention of allergic responses.
Intravenous drugs can cause allergic type reactions - certain anaesthetic agents are more prone to this e.g. muscle relaxants such as alcuronium, vercuronium, atracurium.
Basically even given your history I would not perform any tests on you prior to anaesthesia but would discuss what our options were. There is nothing to suggest you would have a problem with anaesthetic agents and I would just monitor you carefully during your procedure.
Incidentally if you have a tendency to a reaction which leads to hypotension and difficulty breathing as you have described then adrenaline (epinephrine) is the treatment of choice and not an antihistamine.
Kind regards
Dr Ian Jackson