What is it?
Angioedema is sudden swelling that appears when fluid collects in the deeper layers of the skin and of the lining of the mouth. The lip, eyelid, tongue, floor of the mouth and throat are affected most often. The swelling grows within minutes or a few hours, is usually one-sided and feels tight; pain is not marked, and itching may or may not be there.
Telling it apart from the swelling of a dental infection is the first job. Abscess swelling develops over days, hurts when touched, is hot and red, may come with a fever, and has a problem tooth underneath it. In angioedema the swelling is fast, painless, usually has a timing link with a medicine, a food or a contact, and cannot be traced to a single tooth.
What really matters about this picture is the airway. When the tongue, the floor of the mouth and the voice box are involved, the airway can narrow. A change in the voice, noisy breathing, not being able to swallow your saliva and shortness of breath are the signs of that narrowing; none of them is a finding to sit and wait on.
Signs
You will not necessarily have all of these at once.
Why does it happen?
- 01
Allergic triggers
It can start within minutes of contact with medicines, foods, bee and insect stings, and substances such as latex. Hives, itching and redness may go with it. In a dental clinic, latex gloves and the medicines given are asked about under this heading too.
- 02
The non-allergic type linked to a medicine
One group of medicines used to treat blood pressure (ACE inhibitors) can cause swelling even months or years after the medicine was started. Hives and itching are not seen, and the response to allergy medicines stays limited. Do not stop your medicine on your own; tell the clinician who prescribed it.
- 03
Inherited and acquired forms
There is a group in which similar attacks run in the family, hives are not seen, and attacks of abdominal pain may go with it. In these people, dental procedures, injury and physical strain can set off an attack, so a preventive plan needs to be obtained from their own specialist before any procedure.
- 04
Attacks with no trigger found
Attacks where no clear cause can be found despite investigation also occur. Infections, changes in temperature and physical strain can contribute. Not having found the cause does not mean that monitoring and keeping a record are unnecessary.
How does it progress?
- 1
Swelling limited to the lip and face
The swelling is in the lip, the eyelid or the cheek; speech and swallowing are unaffected. Even so, because the picture can spread within hours, it needs to be assessed by a clinician the same day.
- 2
Tongue and floor of the mouth involved
The tongue does not fit in the mouth, speech becomes slurred and swallowing saliva becomes difficult. At this stage the airway is at risk and the assessment is carried out in an emergency department.
- 3
Voice box involved
The voice becomes hoarse, and wheezy breathing and shortness of breath begin. This is a picture in which minutes matter; call 112, and the person should not set off in their own car.
- Afterwards
The period after an attack
The swelling usually settles within a day or two. Even once the attack has passed, it is not left without looking into the cause, because the next attack may run a more severe course.
How is it treated?
This is not treated in dentistry. If the tongue, the floor of the mouth or the throat is involved, if the voice has changed, or if breathing has become difficult, call 112 and do not set off in your own car. The assessment is carried out in an emergency department; there the airway is made safe first, and the treatment is given there too. Even with swelling limited to the lip, you need to be seen by a clinician the same day.
Once the attack has passed, it is time to look into the cause. For adults the place to go is allergy and immunology, and for children paediatric allergy. If the swelling is thought to be linked to a medicine, you are referred to the clinician who prescribed it, and if an inherited form is suspected, to immunology. Testing and diagnosis are the work of those departments; a dentist does not carry out allergy testing and does not diagnose allergy.
The clinic's role is to notice it, stop the procedure and get you to the right place. If swelling starts during an appointment, the procedure is halted, emergency help is called, and the medicines given and the materials used that day are written down with the times and handed over. That record is the most useful part of the allergy assessment that follows.
- If the voice has become hoarse, or there is wheezy breathing or shortness of breath, call 112.
- If your tongue does not fit in your mouth, or you cannot swallow your saliva, this is not something to wait out.
- If the swelling is growing within minutes, or comes with widespread hives, vomiting, dizziness or a feeling that you are about to faint, go to an emergency department.
- If the swelling started straight after a medicine was taken or after a dental procedure, it needs assessing the same day.
How is it prevented?
- Carry a written list of the medicines and substances that have made you swell before, and show it to your clinician at every visit.
- If you have a diagnosed allergy, keep the emergency plan your clinician gave you with you, along with your auto-injector if you have one.
- If you have had lip or tongue swelling while taking a blood pressure medicine, tell the clinician who prescribed it rather than stopping it yourself.
- If you have a diagnosis of hereditary angioedema, get a preventive plan from your own specialist before any dental procedure and tell the clinic before your appointment.
Frequently asked questions
- Could this swelling be a dental abscess?
- The difference usually lies in the speed and in the pain. An abscess grows over days, is hot and painful, has a problem tooth underneath it and may come with a fever. Angioedema develops within minutes, is painless, and cannot be explained by a single tooth. An examination makes the distinction for certain; but if breathing or swallowing is affected, go to an emergency department without waiting for that distinction.
- Would taking an antihistamine be enough?
- This is not something for you to decide on your own. Allergy medicines may work in the allergic type, while the response stays limited in the medicine-related and inherited types; waiting creates a risk for the airway. If the throat, the tongue or breathing is affected, emergency help should be called instead of looking for a medicine.
- Can the numbing injection used in dental treatment cause swelling?
- True allergy to the local anaesthetic itself is rare; behind the swelling there is usually an additive in the solution, another medicine used the same day, or latex. That is why, when swelling happens, a record of every substance used is asked for, and the assessment is carried out in an allergy and immunology department.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.