What is anaphylaxis?
Anaphylaxis is a severe, potentially life-threatening allergic reaction. It can occur within seconds or minutes of exposure to something you’re allergic to, such as food, certain medications, insect stings or latex.
The most common anaphylaxis signs and symptoms include:
- Skin reactions, including hives and itching and flushed or pale skin
- Low blood pressure
- Constricted airways and a swollen tongue or throat, which can cause wheezing and trouble breathing
- A weak and rapid pulse
- Nausea, vomiting or diarrhea
- Dizziness or fainting
Anaphylaxis requires an injection of epinephrine and a follow-up trip to an emergency room. If not treated immediately, anaphylaxis can be fatal.
What is mild anaphylaxis?
Mild anaphylaxis is a less severe allergic reaction that involves some, but not all, of the common anaphylaxis symptoms. The reaction may not progress to full anaphylaxis.
With mild anaphylaxis, you may experience only one or two symptoms, such as:
- Itchy skin, hives or flushing
- Mild respiratory signs, such as nasal stuffiness or coughing
- Mild gastrointestinal signs, such as nausea, cramping or diarrhea
The reaction can occur within minutes after exposure to an allergen. Symptoms may start to go away on their own or after taking an antihistamine.
Can mild anaphylaxis become severe?
Mild anaphylaxis can potentially progress to a severe, life-threatening reaction. But prompt treatment with an epinephrine injection can stop the reaction from worsening.
According to guidelines from the American Academy of Allergy, Asthma & Immunology, if you have any respiratory difficulties or cardiovascular signs of anaphylaxis — such as throat tightness, wheezing, lightheadedness, chest tightness or a faint pulse — you should immediately use epinephrine and seek emergency care.
What causes mild anaphylaxis?
The most common causes of mild anaphylaxis are:
- Food, such as peanuts, tree nuts, fish, shellfish, eggs and milk
- Medications, including antibiotics and nonsteroidal anti-inflammatory drugs (NSAIDs)
- Insect stings, from bees, wasps, hornets, yellow jackets and fire ants
- Latex
- Exercise
In some cases, the cause is unknown. This is more likely if you’ve had only mild symptoms and they occurred long after exposure to a suspected allergen.
Who’s at risk of mild anaphylaxis?
Anyone who has allergies can experience mild anaphylaxis or progress to full anaphylaxis. Risk factors include:
- Having a history of anaphylaxis or severe allergic reactions
- Having asthma, especially if poorly controlled
- Having food allergies and a history of severe reactions to trace exposures
Young children with food allergies also have an increased risk of anaphylaxis. For unknown reasons, males ages 13 to 24 appear to be at the greatest risk of fatal anaphylaxis.
Is mild anaphylaxis always mild?
Not necessarily. Even if you’ve only had mild reactions before, your symptoms could rapidly worsen with your next exposure.
According to one study, about 20% of people with mild anaphylaxis went on to experience moderate to severe anaphylaxis when encountering their allergen again.
It’s important to realize that you can’t reliably predict whether your next reaction will be mild or severe based on previous ones. Any anaphylactic reaction should be evaluated promptly by an allergist.
How is mild anaphylaxis diagnosed?
To diagnose mild anaphylaxis, your doctor will review your symptoms and their timing in relation to exposure to a possible allergen. Be prepared to describe:
- Your signs and symptoms
- How soon symptoms appeared after exposure
- How long symptoms lasted
- Any treatments you used and whether they helped
Your doctor will likely order allergy testing to help confirm or identify your triggers. Skin prick tests and blood tests can detect sensitization to common allergens. In some cases, an oral food challenge may be done under close supervision.
How is mild anaphylaxis treated?
Treatment of mild anaphylaxis involves:
- Antihistamines. Antihistamines like diphenhydramine (Benadryl) can help relieve symptoms like itching, hives and nasal congestion. But they aren’t sufficient treatment.
- Epinephrine. If there are any signs of respiratory, cardiovascular or gastrointestinal involvement, epinephrine (adrenaline) should be used. This helps relax airway muscles, improve blood pressure and reduce swelling and hives.
- Follow-up care. Even if symptoms resolve with antihistamines or epinephrine, you should be evaluated in an emergency room. Symptoms can recur after initial improvement. You’ll also need help identifying triggers and may need to carry epinephrine.
Your doctor can provide prescriptions for epinephrine auto-injectors like EpiPen to have on hand. You’ll learn when and how to use them to treat anaphylaxis.
How can mild anaphylaxis be prevented?
The key is to avoid exposure to your known allergens:
- Carefully read ingredient labels and avoid foods containing your allergens.
- Ask about ingredients when eating out. Avoid restaurants where cross-contact is likely.
- Create an allergen-free zone at home. Don’t allow foods with your allergens in the house.
- Have injectable epinephrine with you at all times.
- Consider immunotherapy, also known as allergy shots. These can reduce sensitivity to some allergens over time.
Wearing a medical alert bracelet can help identify your allergy in an emergency situation.
What’s the long-term outlook with mild anaphylaxis?
With prompt and proper treatment, most cases of mild anaphylaxis resolve without complications. But there are some long-term concerns to be aware of:
- Your reactions could become more severe over time.
- Accidental exposure is still possible despite precautions.
- Mild anaphylaxis can be fatal in rare cases if not treated.
- Quality of life can be significantly impaired by needing to constantly avoid allergens.
- Anxiety may develop about potential reactions.
To reduce risks, work closely with an allergist. They can help you develop an anaphylaxis action plan, prescribe epinephrine, and determine if you’re a candidate for immunotherapy.
With proper prevention and treatment, those who experience mild anaphylaxis can still live full, active lives. Being prepared if a reaction occurs is key.
Conclusion
Mild anaphylaxis causes a limited number of allergy symptoms and isn’t always life-threatening. But there’s still potential for severe reactions to develop, especially if mild symptoms aren’t promptly treated.
Having injectable epinephrine available, avoiding triggers, and regular follow-up care with an allergist are important for staying safe. While mild anaphylaxis may not require an emergency room visit every time it occurs, seeking evaluation is recommended to reduce future risks.