For anyone who carries an adrenaline pen, or lives, works or eats with someone who does · 11 minutes
Adrenaline is the first treatment for anaphylaxis, not the last resort. And the person having it must not stand up.
Almost everything that goes wrong in a severe allergic reaction comes from two beliefs. The first is that adrenaline is a drastic step to be held back until things are clearly terrible — so it is given late, or after an antihistamine that does nothing for the dangerous part. The second is barely known at all: that someone in the middle of a severe reaction should be kept lying flat, because standing up or walking can stop a heart that adrenaline would otherwise have saved. Both are fixable with one page.
Thighouter mid-thigh, through clothing, at the first sign — not later
Flatlie down and stay down; sit only if breathing is hard, never stand
112always, even when the pen works and the person feels better
Giving adrenaline to someone who turns out not to need it is a very small risk. Waiting to be sure is how people die of allergies, and the delay is the single most common finding in fatal cases.
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Adrenaline into the outer thigh, nowThrough clothes if needed. Note the time.
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Lie them flat — legs up if you canSitting is allowed if breathing is hard. Standing and walking are not.
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Call 112 and say "anaphylaxis"Even if they improve. Stay with them.
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No better after 5 minutes? Second doseOther thigh, second pen. Keep both used pens for the crew.
What are you seeing?
Tap everything that fits. Anaphylaxis is not a single symptom — it is a reaction that has reached the airway, the breathing or the circulation, or that involves two body systems at once after a likely trigger. This works out which of those you are describing.
Nothing is saved or sent anywhere. This does not diagnose anything — if you are unsure, treat it as anaphylaxis. Adrenaline given unnecessarily is a much smaller risk than adrenaline given late.
Giving the injector, without hesitating
Every device works slightly differently, and the one thing they share is that the dose goes into the muscle on the outer side of the mid-thigh. Practise with a trainer device — every brand supplies one, they are free, and two minutes with it now is the difference between acting and fumbling.
Get the pen and read nothing. Take it out of the case. Do not go looking for the leaflet, and do not send anyone to another room to fetch a second opinion.
Blue to the sky, orange to the thigh — or whatever your device's version of that is. Remove the safety cap. Devices differ: some need a firm push until it clicks, some have a shorter needle, some are held for three seconds and some for ten. Know yours.
Outer middle of the thigh, at a right angle, straight through clothing if that is faster. Not the buttock, not the arm, not the vein. Hold it in place for the time your device specifies, then rub the site for ten seconds.
Write down the time. On your hand if necessary. The crew will ask, and the five-minute decision about a second dose depends on it.
Keep the used device and hand it over. It tells the ambulance crew exactly what was given, and it is the record if the person cannot speak for themselves.
Stay with them, and keep them still until the ambulance arrives — even if they look completely better within a minute, which is what a working dose of adrenaline looks like.
If you are the one having the reaction: give it to yourself early, sit or lie down immediately, and phone for help from the floor. Do not drive, do not walk to a neighbour, and do not go and lie down alone somewhere quiet — being alone and unobserved is a repeated finding in fatal cases.
The rule almost nobody has been told: stay lying down
In severe anaphylaxis the blood vessels leak and dilate, so a large volume of fluid leaves the circulation in minutes. Lying flat keeps blood returning to the heart. Standing up removes that return, and a heart that has very little to pump can stop — sometimes within seconds of getting to their feet, sometimes just after adrenaline was given and everything seemed to be improving.
So the posture is part of the treatment. Lie them flat, raise the legs if that is easy. If breathing is the main problem, let them sit up — but sitting on the floor, leaning against something, not perched on a stool. If they vomit or are unresponsive but breathing, roll them onto their side. Never let them stand, walk, run for the injector, go to the bathroom, or "just get to the car".
Do not sit them up on a chair to make them comfortable. If they collapse from a chair the fall itself is a second injury, and upright is the problem.
Bring the injector to the person rather than the person to the injector. Send someone else, or shout for it.
Do not send them off to a first-aid room down a corridor. Treat where they are and let the ambulance come to you.
Keep them down after they improve. The temptation to get up and carry on is enormous, particularly in a teenager who is embarrassed. This is exactly when the danger is highest.
If they are pregnant, lie them on their left side rather than flat on their back.
After the pen works
Adrenaline is fast and it wears off. A reaction can come back as the drug fades, sometimes hours later, and that second wave can be worse than the first — which is why the ambulance still comes even when the person is sitting up asking what the fuss was about.
Always go to hospital, and always by ambulance. Not by car with a relative driving: the person needs to stay lying down and monitored, and the crew carry oxygen, fluids and more adrenaline.
Expect to be observed for some hours. The exact time depends on how severe it was and how quickly it settled; being sent home early is a decision for the team, not the family.
Replace the used injector the same day, and get the second one checked. Being left with no pen after a reaction is a common and dangerous gap.
Ask for an allergy referral before you leave. After an unexplained anaphylaxis, identifying the trigger is the whole prevention plan — and for insect stings there is a desensitising treatment that is extremely effective.
Write down what happened while it is fresh: what was eaten or done, how long before the symptoms, what the symptoms were and in what order, what was given and when. This is the most useful thing anybody brings to an allergy clinic.
Expect to feel shaky, headachy and unsettled afterwards. That is the adrenaline, not a complication, and it passes.
Four things that do not treat anaphylaxis
Not treatments
An antihistamine. It helps itching and hives. It does nothing for a swelling airway or a falling blood pressure, and reaching for it first is how the adrenaline gets delayed.
An asthma inhaler alone. If the person has asthma, use it after adrenaline — but wheeze in an allergic reaction is not an asthma attack, and treating it as one is a documented route to a death.
Waiting to see. There is no version of "let us see how it develops" that beats treating early. Reactions can go from itchy mouth to collapse in minutes, and previous mild reactions do not predict this one.
Making them vomit, or drinking water to "wash it down". Neither removes an allergen that is already absorbed, and both raise the risk of choking.
What is true
Adrenaline works within minutes and is very safe in a healthy body at this dose, even if the diagnosis turns out to be wrong.
A pen through jeans works. Fabric is not the obstacle people imagine.
An expired pen is better than no pen if it is all you have — then call for help immediately and say so.
A reaction with no rash at all can still be anaphylaxis. Up to a fifth have no skin signs, and that absence is a reason more deaths are missed, not fewer.
The question is never "is this bad enough for adrenaline?" It is "is there any chance this is anaphylaxis?" — because the answer to the second one has a treatment, and hesitating does not.
Who is at higher risk, and what makes a reaction worse
Poorly controlled asthma is the single biggest risk factor for a fatal food reaction. Taking the preventer inhaler every day is genuinely part of allergy safety, which almost nobody is told.
Teenagers and young adults are over-represented in deaths — a mix of risk-taking, eating out, not carrying the pen, and not wanting to make a scene in front of friends. The pen in a bag at home has never saved anyone.
Cofactors lower the threshold on the day: exercise before or after eating, alcohol, heat, infection, tiredness, menstruation, and anti-inflammatory painkillers. A food tolerated on Monday can cause a reaction on Saturday for exactly these reasons.
Being alone, or upright, or far from help turns a survivable reaction into a fatal one more often than the severity of the allergy itself.
Insect stings and medicines cause more fatal reactions in adults than food does; food dominates in children.
A previous mild reaction is not reassurance. Severity varies with the dose, the cofactors and the day. Many fatal first reactions follow years of minor ones.
Living with it: the boring things that work
Habits
Two injectors, always, in the same place — one is not enough because a third of reactions need a second dose
Check expiry dates on a fixed date each year, and look at the liquid: discoloured or cloudy means replace
Keep them at room temperature, out of the car glovebox in summer and the freezer in winter
Everyone in the house, and the school, knows where they are and has held a trainer device
A written emergency plan on the fridge and in the school bag, with the person's photo and doses
A medical bracelet or a phone lock-screen note for the day nobody who knows is there
Scripts
Restaurants: name the allergen, ask for the manager, and use the word allergy, not "I don't like". Ask what is in the oil and on the grill.
"May contain" labels mean an unquantified risk of cross-contamination — for a severe allergy, treat them as containing it.
Schools: the pen stays with the child or in an unlocked known place, never in a locked office.
Teenagers: agree that friends get told, in one sentence, and shown where the pen is. It is the single best predictor of a good outcome away from home.
Travel: carry pens in hand luggage with the prescription label, and learn the local emergency number.
The phone call, and who is allowed to help
Two practical things that get in the way at the moment they matter.
What to say
"Anaphylaxis" — the word first. It routes the call differently from "an allergic reaction" or "she has come out in a rash", and it tells the dispatcher what is coming.
The age, and the address, slowly. Give the address before the story: if the call drops, the crew still comes.
What happened, in one line. "She ate a biscuit ten minutes ago, her throat is tight, she has hives."
That adrenaline has been given, and at what time. This is the single most useful sentence in the call, because the five- and fifteen-minute decisions run from it.
Then put the phone on speaker and leave it on. The dispatcher will talk you through the rest, and you need both hands and no walking.
Who can give the injector
People hesitate because they are not sure they are allowed. In an emergency, in most countries, a bystander may use an auto-injector on someone who needs it — including a device that belongs to that person, and in many places a spare device held by a school or workplace. Rules on unassigned "spare" devices differ by country, so if you are responsible for a school, a nursery or a restaurant, look up your own — but nobody has ever been in trouble for helping someone who was collapsing.
And if you are the person with the allergy: tell the people you are with, out loud, before anything happens — where the pens are and that they should use one if you cannot. A friend who has held a trainer device once will act; a friend who has never seen one will look for an adult. This one conversation is worth more than the whole of the rest of this page.
Babies, children, and the hopeful part
A small child having a severe reaction can look different: sudden floppiness or unusual sleepiness, pallor, a hoarse or silent cry, vomiting shortly after a new food, or an infant who goes quiet rather than distressed. Trust a sudden change after a food more than you trust a rash.
Dose devices are weight-based and a child's device changes as they grow, so the prescription needs revisiting rather than repeating for years.
Teach children to say one sentence — "I think I am having an allergic reaction" — and to tell an adult rather than going somewhere quiet. Going off alone to be sick is a repeated pattern in the worst cases.
Nurseries and schools should have a plan, not a pen in a cupboard. Ask who is trained, where the device is, and what the plan says about calling an ambulance.
And the hopeful part, for anyone with a baby. The old advice to delay peanut and egg was wrong. Introducing common allergenic foods in infancy, once solids have started and alongside everything else, substantially reduces the chance of developing an allergy — the effect is large and the trials are clear. If your baby already has severe eczema or a known food allergy, do it on medical advice rather than alone at home. This is the rare part of this subject where an ordinary decision at six months genuinely lowers the odds of ever needing the rest of this page.
The drill: 16 minutes that matter
Sixteen ordinary moments — a school trip, a restaurant, a teenager who wants to walk it off, a rash with no wheeze. Most have an instinctive answer that delays the one thing that works. Pick your move; every answer explains why.
The card
Print it for the fridge, the school bag and the pen case. Whoever is standing there needs the four steps, not the theory.
SEVERE ALLERGIC REACTION — ACT NOW
ADRENALINE IF ANY OF THESE
Hoarse voice, tight or swollen throat, trouble swallowing
Wheeze, persistent cough, struggling to breathe
Pale, floppy, dizzy, collapse, sudden sleepiness in a child
Rash or swelling plus vomiting or severe tummy pain
Any fast-worsening symptoms after a known allergen
THE FOUR STEPS
Adrenaline — outer mid-thigh, through clothing. Note the time
Lie flat, legs up. Sit only if breathing is hard. Never stand or walk
Call 112, say "anaphylaxis". Stay with them
No better after 5 min — second pen, other thigh
NEVER
Never give an antihistamine instead of adrenaline
Never let them stand up, walk, or go to the bathroom alone
Never skip the ambulance because they got better
If you are unsure whether it is anaphylaxis, give the adrenaline. Late is the danger, not early.