If there is doubt, it is sometimes best to use the treatment for anaphylaxis, but the treatment should then be reviewed with a doctor because unnecessary treatment for anaphylaxis is a bad idea. Learn the rules for knowing when to treat, to minimise the chance that you will use the treatment when you should not. Anaphylaxis Fainting Colour Pink, typically Pale, typically Pulse Fast, usually Slow, usually Blood pressure Can remain low lying down Normal when lying down Other features which may be present Nettlerash Swelling Difficulty breathing Tummy pain or diarrhoea The person has probably fainted before. People who are allergic to foods often notice the effect in seconds, and their life may be in jeopardy within a few minutes. Sometimes a reaction takes much longer to start, an hour or so, but can still be extremely serious.
Improvement can also happen quickly, especially with the right treatment.
A few people then have a second wave of anaphylaxis, so people who have had a serious anaphylactic reaction to nuts should be observed medically for about six hours or overnight. It is possible for anaphylaxis to be mild and to need little or no treatment. You would not think so from most of the information you read. Of course a life-threatening attack of anaphylaxis may look mild in its early stages, so you need to go for medical help just in case, and need to have the emergency treatment immediately available in case things start to go more badly wrong. In most cases it is better to err on the side of treating anaphylaxis early rather than to leave treatment rather late.