Allergic Reactions: When It’s an Emergency

Call 911 now if there is trouble breathing, swelling of the lips, tongue or
throat, a tight or hoarse voice, trouble swallowing, faintness or collapse, or a
spreading rash together with vomiting. That is anaphylaxis, and it is a
life-threatening emergency.

If you have an epinephrine auto-injector prescribed to you, use it first and
then call 911. Using it early is what saves lives; waiting to see whether it
gets worse is the most common reason anaphylaxis turns fatal.

Everything below is for people who have a moment to read.

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How fast this can move

Anaphylaxis can go from a tingling mouth to a closed airway in minutes. That
speed is the single most important thing to understand about it, because it is
what makes "wait and see" so dangerous — the reaction you are watching may not
be the reaction you end up with.

It is not always fast. Some reactions build over an hour. You cannot tell at
the start which kind you have, which is why the threshold for acting is low.

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When it is an emergency

Any one of these on its own is enough. You do not need the full list.

• Breathing — wheezing, chest tightness, shortness of breath, a barking or
  hoarse voice
• Airway — swelling of the lips, tongue or throat; trouble swallowing; a
  feeling of something closing
• Circulation — faintness, dizziness on standing, pale or grey skin,
  collapse
• Gut with skin — vomiting or severe cramping together with hives or
  flushing, which is a recognised anaphylaxis pattern and gets missed because
  people read it as food poisoning
• A sense that something is badly wrong. People in anaphylaxis often
  describe it before their signs are obvious. Take it seriously.

Two or more body systems involved at once — skin plus gut, or skin plus
breathing — means treat it as anaphylaxis.

And do not wait to work out what caused it. The National Library of
Medicine's summary notes plainly that sometimes no cause can be found.
Anaphylaxis is recognised by what the body is doing, not by identifying an
exposure — so "I'm not allergic to anything" is not a reason to wait, and a
first reaction in someone with no known allergy looks exactly like any other.

Reactions that stay small — and why they still get watched

Some reactions stay in one place and stay mild: a few hives, a local itch, a
mildly runny nose, a small area of swelling at a sting site and nothing else.

Mild at the start is not a promise about the next hour. Reactions escalate,
and the escalation is what matters — a rash that is spreading, or any new
symptom in a second body system, changes the picture entirely.

If it worries you, come in. We are open every hour, you do not need an
appointment, and an allergic reaction that turns out to have been small is a
good result rather than a wasted trip.

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Why you should not go home just because it settled

This is the part most articles leave out, and it is the reason this one exists.

A reaction that responds to epinephrine can come back hours later, sometimes
four to twelve hours afterwards, without a second exposure to anything. It is
called a biphasic reaction. The second wave can be as bad as the first, and by
then the injector may be used up and the person may be asleep.

So an injector is not the end of the episode. It buys time to get to an
emergency room.

This is also where a freestanding emergency room is genuinely useful rather than
merely nearer: we can hold and monitor you here for up to 24 hours, which
means a reaction that settles can be watched properly instead of being sent home
early or transferred to a hospital simply because nobody could keep you.

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What happens when you arrive here

• A physician sees you — board-certified, every visit, at every hour.
• Treatment for the reaction itself, including the severe end of it.
• A critical care room in this building for the presentations that need one.
• Monitoring for up to 24 hours, which for a significant reaction is the
  point of coming in rather than riding it out.
• Laboratory and imaging on site if the picture is unclear — and it often
  is, because several things mimic an allergic reaction.

If you need admission or hospital-level inpatient care, we stabilise you here
and arrange the transfer. We are an emergency room, not a hospital. Most
people are treated and go home.

Bring the injector with you, used or not, and anything you can identify as
the trigger — a wrapper, a label, a photo of the plant or insect. It genuinely
changes what we look for.

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If you carry an auto-injector

• Carry two. One dose is often not enough, and a second is frequently
  needed before help arrives.
• Use it early rather than late. Hesitation is the pattern in fatal cases,
  and epinephrine given early to someone who turned out not to need it is a far
  better outcome than the reverse.
• Check the expiry date, and replace it before the season you most need it.
• Tell the people you are with where it is. Somebody in anaphylaxis may not
  be able to tell them.
• Still call 911 after using it, and still get assessed. See the biphasic
  section above.

Do not use someone else's injector unless emergency services tell you to,
and do not rely on antihistamines for a severe reaction — they do not treat
an airway or a collapse, and taking one can create a false sense that the
episode is handled.

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Children

We are not a pediatric emergency room, and we treat children every day. Food
allergy reactions in children are one of the commoner reasons families come in,
and the threshold for a child is lower, not higher: they are smaller, they
deteriorate faster, and they are less able to describe what they feel.

If a child has any airway or breathing symptom, call 911.

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El Mirage ER — open 24 hours a day, 7 days a week, 365 days a year.
12000 N El Mirage Rd, El Mirage, AZ 85335 · (480) 237-4922
Walk in. No appointment, no referral.
If this is a medical emergency, call 911.

This article explains when to seek emergency care. It is not medical advice and
cannot account for your history, your medications, or what is happening to you
now. If you are unsure, call us or call 911.

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Sources

The guidance in this article about when to seek emergency care is drawn
from these public sources. Each one is linked so you can read it yourself.

• MedlinePlus (National Library of Medicine) — Anaphylaxis — https://medlineplus.gov/anaphylaxis.html

This article is general information, not a diagnosis, and it cannot account
for your history or medications. If you are unsure, call us on (480) 237-4922
or come in. If it might be an emergency, treat it as one and call 911.

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