Symptoms

Allergic reaction abroad? How to tell if it is an emergency

Most allergic reactions on a trip are mild and stay in one place. A few are anaphylaxis, which needs emergency care in minutes. This is how to tell them apart, and what to do with each.

Pomodoc editorial team1 October 202610 min read

General information, not a diagnosis. If you are worried about your symptoms, speak with a doctor.

The short answer

An allergic reaction is an emergency if it involves swelling of the lips, mouth, tongue or throat, difficulty breathing or swallowing, wheezing or a hoarse voice, feeling faint or confused, or skin that turns blue, grey or pale. That can be anaphylaxis: use an adrenaline auto-injector if you have one, call the local emergency number (112 anywhere in the European Union), and lie down rather than stand. Go to hospital even if you feel better. A reaction that stays mild and in one place, such as a few itchy hives, a rash on one arm or sneezing and watery eyes, is not an emergency; a pharmacist can usually help, and a doctor should look at hives that spread, keep returning or have not improved after 2 days.

Worth knowing

Swelling of the lips, tongue or throat, breathing trouble, wheezing, faintness or confusion during a reaction can mean anaphylaxis. Call the local emergency number.
Adrenaline is the treatment for anaphylaxis. An antihistamine is not a substitute, so do not take one and wait.
Mild symptoms in two parts of the body at once, such as hives and vomiting, are treated as a severe reaction.
A few itchy hives or a rash in one place, with nothing else, is usually manageable with a pharmacist's help.
If you have a known serious allergy, carry two adrenaline auto-injectors at all times, in your hand luggage when you fly.

In this guide

A reaction on a trip is frightening partly because everything around it is unfamiliar: a dish you could not read the ingredients of, a sting on a trail, a new medicine from a pharmacy. The first job is not to work out what caused it. It is to work out whether it is an emergency.

Is it anaphylaxis? The signs that mean emergency care

Anaphylaxis is a serious, life-threatening allergic reaction. Symptoms usually start within 5 to 30 minutes of contact with the trigger, occasionally after more than an hour. You should treat a reaction as anaphylaxis if it includes any of these:

Airway: swelling of the throat or tongue, tightness in the throat, a hoarse voice, difficulty swallowing.
Breathing: difficulty breathing or breathing very fast, wheezing, coughing or noisy breathing, chest tightness.
Circulation: feeling faint or dizzy, fainting, skin that feels cold, or blue, grey or pale skin, lips or tongue.
Brain: feeling confused or unusually tired, or a sudden sense that something terrible is happening.

A rash or hives often come with it, but not always, and a reaction can be serious without much on the skin. The other rule that catches people out: mild symptoms in two different parts of the body at once, for example hives together with vomiting, or an itchy mouth together with a cough, are treated as a severe reaction, not two mild ones.

What to do in the first minutes

Use the adrenaline auto-injectorIf you or the person with you carries one, use it straight away. Adrenaline (called epinephrine in the US, and sold under brand names such as EpiPen) is the treatment for anaphylaxis. Do not take an antihistamine instead and wait to see what happens.
Call the local emergency numberSay that you think it is anaphylaxis. 112 works across the European Union free of charge; in the UK it is 999. Call even if there is no auto-injector to use.
Lie down, and stay downLie flat and raise the legs. If breathing is difficult, raise the shoulders or sit up slowly. Do not stand up or walk, even if you start to feel better.
Use a second auto-injector after 5 minutes if neededIf symptoms have not improved 5 minutes after the first injection, use a second one.
Go to hospital, even if it settlesEmergency care is needed after adrenaline whether or not symptoms ease. Hospitals usually keep people in for observation for several hours.

Mild, needs a doctor, or an emergency? A quick comparison

Use this to place what you are seeing. If anything in the bottom two rows applies, treat it as an emergency whatever the rest of the table says.

What you notice	What it usually means	What to do
A few itchy hives or a rash in one area, otherwise well	A mild, localised reaction	Avoid the likely trigger, ask a pharmacist about an antihistamine, and keep watching for new symptoms
Sneezing, a runny nose, itchy or watering eyes	A mild allergy, often to pollen or dust	A pharmacist can suggest an antihistamine
Hives that spread, keep coming back or have not improved after 2 days; swelling under the skin away from the mouth and throat	A reaction that needs a doctor's view	Speak to a doctor promptly, the same day if you can
A sting in or near the mouth or throat, or a sting when you have had a serious reaction before	Higher risk, even if it looks small now	Get urgent medical advice now
Hives or itching together with vomiting, a cough or a hoarse voice	Two body systems: treated as a severe reaction	Emergency: auto-injector if prescribed, then call the local emergency number
Swelling of lips, tongue or throat, breathing difficulty, wheezing, faintness, confusion or colour change	Possible anaphylaxis	Emergency: auto-injector if prescribed, then call the local emergency number

Not every rash on a trip is an allergy. Heat rash, insect bites and infected bites look similar at first and have their own warning signs, covered in our guide to a rash or bite while travelling.

When can a video consultation help with an allergic reaction?

For a non-emergency reaction, yes, and only then. A video consultation can help when the reaction is mild and stays in one place, such as an itchy rash on the arms, a few hives with nothing else, or hay fever symptoms, and there is no swelling of the mouth or throat, no breathing difficulty and no faintness. It is never the route for anaphylaxis.

What a doctor can do on a video call

Look at the rash or hives on camera. Hives can be harder to see on brown and black skin, in person or on screen, so describe how it feels as well: itching, stinging or burning.
Go through what you ate, touched, were stung by or took in the hours before it started.
Advise what to ask a pharmacist for, usually an antihistamine, and whether any long-term condition or medicine you take changes that.
Tell you which changes mean you should stop watching and get emergency or in-person care.

What a call cannot do is examine your airway, give adrenaline or monitor you. That is why everything above this section is about getting emergency help first.

Pomodoc connects travellers with English-speaking doctors by video, licensed to treat you in the country you are physically in. Have three things ready: when it started and how it has changed, what you were exposed to beforehand, and any medicines you have already taken for it.

How to travel safely with a known allergy

If you have had a serious reaction before, most of the protection happens before the trip. A doctor will usually want you to have these in place:

An allergy action plan. A written plan from your own doctor or allergist saying what to do in a reaction. Take copies, including one translated into the local language, and give one to the people you travel with.
Two adrenaline auto-injectors, with you at all times. Not in the hotel safe, and not only at meals: NHS guidance is to carry two at all times, and CDC's is to carry it for every activity, even ones where you do not expect to eat.
Hand luggage, not the hold. Airport rules generally allow essential medicines and medical equipment in hand luggage. A letter from your doctor or a copy of the prescription is sensible, and is required for some liquid medicines. Check your airline's policy before you fly.
Translated allergy cards. A card listing every allergy in the local language, to show restaurant staff and anyone preparing your food. When in doubt about a dish, do not eat it.
A medical alert bracelet or card, and travel companions who know the signs of a severe reaction and where your auto-injectors are.
The local emergency number, saved in your phone on arrival, and your own antihistamine from home so you are not reading foreign labels during a reaction.

Bites and stings are a common trigger away from home. If you are heading somewhere with jellyfish or other sea creatures, our first-aid guide to stings at the beach covers what to do for the sting itself.

In short

Emergency signs: swelling of the lips, tongue or throat, breathing trouble, wheezing, faintness, confusion or colour change.
Then act: auto-injector, local emergency number, lie down, second dose after 5 minutes if needed, hospital even if it settles.
Two systems count: mild symptoms in two parts of the body at once are treated as severe.
Mild and in one place: a pharmacist can usually help; spreading or returning hives need a doctor's view.
Video care is for the mild side only: useful for a rash or hives with no warning signs, never for anaphylaxis.
Known allergy: action plan, two auto-injectors with you at all times, translated cards, emergency number saved.

Common questions

How do I know if an allergic reaction is serious?

A reaction is serious if it affects breathing, the airway or circulation: swelling of the lips, tongue or throat, difficulty breathing or swallowing, wheezing, a hoarse voice, feeling faint or confused, or skin turning blue, grey or pale. Mild symptoms in two body systems at once, such as hives with vomiting, are also treated as severe. Any of these means calling the local emergency number.

Should I take an antihistamine for anaphylaxis?

No. Adrenaline is the treatment for anaphylaxis, and allergy specialists advise against taking an antihistamine and waiting to see if symptoms improve. Use an adrenaline auto-injector if you have one and call the local emergency number. Antihistamines are for mild reactions, such as a few itchy hives or hay fever symptoms.

How long do hives from an allergic reaction usually last?

Hives usually clear up within a few days. NHS guidance is to see a doctor urgently if they have not improved after 2 days, if the rash is spreading or keeps coming back, if you develop a high temperature, or if there is swelling under the skin. Swelling of the lips, mouth, throat or tongue is an emergency.

Can I get an adrenaline auto-injector prescribed abroad by video?

It cannot be promised in advance. A doctor may issue a prescription when it is clinically appropriate and local rules permit, and some medicines cannot be prescribed remotely. A new serious allergy usually needs an in-person assessment and an allergy specialist. If you have lost an auto-injector you already rely on, treat replacing it as urgent: speak to a doctor the same day, and carry your remaining one at all times meanwhile.

How do I fly with an adrenaline auto-injector?

Carry it in your hand luggage, never in the hold, and take two. Airport rules generally allow essential medical equipment in hand luggage; a letter from your doctor or a copy of your prescription makes screening simpler and is required for some liquid medicines. Policies differ between airports and airlines, so check with your airline before you travel.

Sources

AnaphylaxisNHSThe symptom list (throat and tongue swelling, breathing difficulty, swallowing difficulty, hoarse voice, wheezing or noisy breathing, tiredness or confusion, faintness, cold skin, blue, grey or pale skin); calling 999 and saying it is anaphylaxis; using an auto-injector; lying down with legs raised or sitting up slowly if breathing is hard; never standing or walking; a second auto-injector after 5 minutes; hospital observation of around 2 to 12 hours; carrying 2 auto-injectors at all times.
AnaphylaxisAmerican Academy of Allergy, Asthma & Immunology (AAAAI)Anaphylaxis as a serious, life-threatening allergic reaction; onset usually within 5 to 30 minutes, occasionally over an hour; the feeling of impending doom; epinephrine as first-line treatment; the warning not to take an antihistamine and wait; emergency care after epinephrine.
Recognizing and Responding to a ReactionFood Allergy Research & Education (FARE)Giving epinephrine immediately for severe symptoms and calling emergency services; mild symptoms in more than one body area treated as severe; further doses about 5 minutes after the last; going to the emergency department even if symptoms resolve.
AllergiesNHSMild allergy symptoms (runny nose, sneezing, red or watering eyes, a raised rash); antihistamines as a treatment; the 999 signs of swollen lips, mouth, throat or tongue, breathing difficulty, confusion and colour change.
HivesNHSThat hives usually clear within a few days and can be harder to see on darker skin; pharmacist advice on antihistamines and mentioning long-term conditions; seeing a doctor urgently if no improvement after 2 days, a spreading or returning rash, a high temperature or swelling under the skin; the emergency signs.
Insect bites and stingsNHSUrgent advice for stings in or near the mouth or throat and for anyone who has had a serious allergic reaction before; the emergency signs of anaphylaxis after a bite or sting.
Travelers with AllergiesCenters for Disease Control and Prevention (CDC)Carrying epinephrine for all activities; translated allergy cards; copies of the allergy emergency response plan, including in the local language; a medical alert bracelet; travel companions knowing the plan and the signs; asking about ingredients and not eating when in doubt.
Hand luggage restrictions: medicines and medical equipmentGOV.UKThat essential medicines and medical equipment are allowed in hand luggage, and that proof of prescription (a doctor's letter or a copy of the prescription) is required for some liquid medicines.
112, the European emergency numberEuropean CommissionThat 112 is reachable everywhere in the European Union free of charge.