What is anaphylaxis?
It is a serious allergic reaction that may cause death. It can occur in people who have known allergies or asthma; several substances may cause it, such as medicinal products, foods or insect bites.
The symptoms tend to present with re-exposure to the previously-sensitised allergen.
The symptoms of anaphylaxis are triggered between 15 and 30 minutes after the exposure to the allergen. However, sometimes it may start at the time of contact.
It is characterised by difficulty breathing, general malaise and loss of consciousness, and may even cause death.
What are the causes?
Some insect bites (from the Hymenoptera order, mainly bees and wasps) may cause very serious anaphylactic shock.
Food allergies include several foods, such as milk, eggs, peanuts, wheat, soy, fish, shellfish and nuts. The symptoms range from mild, such as itchy mouth, throat and ears ("oral allergy syndrome"), to very serious, such as digestive (diarrhoea, vomiting), skin (urticaria, angiooedema) respiratory (rhinitis, asthma) or generalised (hypotension and anaphylactic shock) symptoms.
What are the symptoms of anaphylaxis?
- General itching, starting on the palms of the hands and soles of the feet
- Skin rash or erythema (generalised urticaria — swelling or wheals)
- Swelling of the face (facial angiooedema), in the throat, mouth, tongue and larynx (angiooedema of the glottis), swelling of other parts of the body.
- Wheezing (whistling noises when breathing that make it difficult to breath)
- Chest tightness
- Scratchy voice
- Difficulty swallowing
- Dizziness, nausea, vomiting
- Diarrhoea, abdominal cramps
- Pale or reddish skin due to generalised rash
- Sudden drop in blood pressure, loss of consciousness
- Palpitations (tachycardia)
Anaphylaxis is a medical emergency that requires immediate care.
Is anaphylaxis common?
It is estimated that every year around 100 people die due to anaphylactic reactions secondary to food ingestion; and around 40 die as a result of insect bites.
How is anaphylaxis treated?
If you have a history of a possible allergy to any compound, your allergist or allergy specialist should perform an evaluation, diagnosis and provide suitable treatment.
Once the diagnosis has been performed, you will be given a treatment plan and informed of how to avoid contact with the possible allergens that may cause you anaphylaxis.
For example, if you are allergic to latex, you should not use gloves or balloons or natural rubber latex materials.
If you are allergic to some type of food, you should avoid them and even take care with those foods produced in the presence of those ingredients.
If you have a serious allergy to insects (bees or wasps), avoid spending time outside during the insect season, such as spring or summer. Talk to your doctor about the possibility of immunotherapy (injections against the allergy to Hymenoptera venom or insects such as bees or wasps) to protect yourself against future reactions.
The treatment commonly used to control anaphylactic reactions is epinephrine or adrenaline; in any case your allergist will inform you regarding the treatment.