Anaphylaxis

As anaphylaxis is a generalized systemic reaction, a wide variety of clinical signs and symptoms involving the skin, gastrointestinal and respiratory tracts, and cardiovascular system can be observed. The most common clinical manifestations include:

• Cutaneous (skin) symptoms:
  • Red, hot, and itchy rashes
  • Pale and cold skin
  • Urticaria (skin rashes)
• Respiratory symptoms:
  • Wheezing
  • Stridor (high-pitched sound on respiration)
  • Difficulty in breathing
  • Gasping
  • Bronchospasm (tightness of muscles lining the lungs)
• Cardiovascular symptoms:
  • Tachycardia (increased heart rate)
  • Hypotension (low blood pressure)
  • Bradycardia (decreased heart rate)
• Gastrointestinal (GI) symptoms:
  • Nausea
  • Vomiting
  • Abdominal pain
  • Diarrhea
• Neurological symptoms:
  • Lightheadedness
  • Confusion
  • Loss of consciousness
• Conjunctival (eye) symptoms:
  • Erythema (redness)
  • Pruritus (itching)
  • Excessive tearing
• Other symptoms:
  • Sense of impending doom
  • Tingling
  • Anxiety
  • Metallic taste in the mouth
  • Laryngeal edema (swelling in the throat)
  • Uterine cramps and bleeding

Triggers generally cause anaphylaxis, and it is crucial to identify the specific trigger for the reaction. The most common triggers include:

• Food: Common triggers include peanuts, walnuts, pecans, fish, shellfish, cow’s milk, eggs, red meat, prawns, shrimp, and lobster. There is a test available that measures the levels of allergen-specific antibodies to identify food allergies.
• Medications: This includes antibiotics (such as penicillin and cephalosporins), NSAIDs (like diclofenac, disprin, and paracetamol), anesthesia drugs, muscle relaxants, β-blockers, and ACE inhibitors.
• Latex: Found in gloves, IV tubes, syringes, adhesive tapes, and catheters. Healthcare workers, children with spina bifida and genitourinary abnormalities, and individuals who work with natural latex are at a higher risk for latex-induced anaphylaxis. It is advisable to shop for latex-free products.
• Insect stings: Common triggers include bees, wasps, hornets, yellowjackets, and fire ants.
• Vaccines: Some patients may develop anaphylaxis following immunization. The majority of cases of vaccine-associated anaphylaxis are linked to vaccinations for measles, mumps, and rubella (MMR), Japanese encephalitis, diphtheria, tetanus, and pertussis (DPT), as well as hepatitis A and B.

Anaphylaxis is a life-threatening type I hypersensitivity reaction, triggered by exposure to a wide range of antigens that involve multiple organ systems. Risk factors for anaphylaxis include:

• Cardiovascular diseases: Preexisting cardiovascular disease is a risk factor for fatal anaphylactic reactions or lasting morbidity due to myocardial infarction (heart attack) or stroke induced by anaphylaxis.
• Asthma: Poor asthma control remains a risk factor for severe anaphylaxis, especially in children. The second Tuesday of May is observed as World Asthma Day to raise awareness about the condition and its management.
• Mastocytosis: This rare condition is caused by an excess number of mast cells (a type of immune cell) gathering in the body's tissues. Adult patients and children with extensive skin disease due to mastocytosis have an increased risk of developing severe anaphylaxis.
• Age: The first anaphylactic episode is most commonly observed in the age group of 0–2 years. Additionally, older age has been consistently associated with a higher rate of fatal drug anaphylaxis.
• Previous anaphylactic reaction: The risk of a serious reaction increases if an individual has experienced anaphylaxis once, with future reactions potentially being more severe than the first.
• Gender: Adult women experience anaphylaxis induced by food, drugs, and radiocontrast agents, as well as idiopathic anaphylaxis, more frequently than adult men.
• Alcohol: Allergy to alcohol can cause symptoms ranging from mild, such as an itchy mouth or eyes, to severe, including vomiting or anaphylaxis.
• Exercise: Exercise-induced anaphylaxis is a rare but potentially life-threatening clinical syndrome, where the association with physical activity is crucial. The range of activities can be as mild as walking.

To diagnose your risk of anaphylaxis or to determine whether previous symptoms were anaphylaxis-related, your allergist/immunologist will conduct a thorough investigation of all potential causes that include:

• Medical history: Your allergist will ask for specific details regarding all past allergic reactions. Clinical history along with allergy testing is used in the identification of allergen triggers.
• Laboratory tests: Medically supervised allergen challenges may also be undertaken to confirm a diagnosis or determine if a patient has outgrown an allergy. Tests to identify sensitization to an allergen include:
• Skin prick test: This test inspects for immediate allergic reaction to different allergens at the same time. It is usually performed on the forearm in adults and on the upper back in children.
• Serum-specific IgE: This test, formerly known as RAST (Radioallergosorbent testing), measures how much IgE your body makes in response to a single allergen and is preferred when the skin prick test is not suitable or not available.
• Serum enzyme tryptase: Tryptase is released from mast cells during anaphylaxis. The level can be raised for three hours after the reaction. Levels greater than 11.5 ng/mL are considered elevated.
• SC5b-9: This test measures the complement system activation, which can be elevated shortly after a severe allergic reaction.

Note: Testing for allergen-specific IgE food mixes is not recommended as it does not indicate which foods from the mix the patient is allergic to and may result in unnecessary avoidance of foods.

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If you have a serious allergy or have experienced anaphylaxis in the past, it's important to try to prevent any future episodes. This can be achieved by keeping the following in mind:

• Identify the triggers: Finding out what you are allergic to can help you avoid future episodes of anaphylaxis.
• Avoid those triggers: If a trigger has been identified, take steps to avoid it whenever possible. Here are some common triggers and ways to avoid them:
• Food:
  • Check food labels for ingredients.
  • Inform restaurant staff about your allergies to ensure they are not included in your meal.
  • Be aware of foods that may contain small traces of potential allergens.
• Insect stings:
  • Move away from wasps, hornets, or bees slowly without panicking.
  • Use insect repellent when spending time outdoors, especially in summer.
  • Be cautious when drinking from cans in the presence of insects.
  • Avoid walking outside with bare feet.
• Medicines:
  • If allergic to certain medicines, consult your doctor for safe alternatives.
• Always carry adrenaline auto-injectors: You may be prescribed an adrenaline auto-injector if there is an ongoing risk of developing anaphylaxis. Keep the following in mind while using an auto-injector:
• Always carry two in-date auto-injectors at all times.
• Ensure you and any caregivers know when and how to use the auto-injector.
• Regularly check the expiry date and replace it before it expires.
• Do not delay injecting yourself if you suspect you may be experiencing anaphylaxis.
• Try allergy shots (immunotherapy): For many people, allergy shots can help lower the risk of anaphylaxis and decrease the severity of reactions.

The treatment of anaphylaxis depends on the patient's ability to describe the situation. If the patient is unconscious or not fully conscious, understanding the symptoms becomes crucial. Anaphylaxis treatment includes:

Medications

The medications used to treat an anaphylactic reaction include:

• Adrenaline (Epinephrine): This is the first line of treatment recommended for patients with anaphylaxis. This drug can be life-saving as it plays an important role in delaying the progression of life-threatening reactions.
• Antihistamines: Antihistamines reduce inflammation in air passages and improve breathing. H1 antihistamines such as diphenhydramine or cetirizine can also relieve itching and hives.
• Beta Antagonists: These are used for airway protection and to relieve respiratory tract symptoms.
• Glucocorticoids: Steroids (glucocorticoids) are often recommended in anaphylaxis. They reduce the severity of the acute reaction and the risk of recurrence.

For Hospital-Based Patients

For patients who have been stabilized in a hospital setting, the following agents are used:

• Activated Charcoal: This solution is commonly used to treat poison victims and individuals with peanut allergies. Drinking activated charcoal immediately after accidental exposure to peanuts can block further absorption of allergy-causing proteins in the body and reduce the severity of the allergic reaction.
• Vasopressors: Norepinephrine, vasopressin, and other pressors are helpful for patients suffering from anaphylaxis with refractory hypotension (persistent hypotension in resuscitated patients).
• Glucagon: This anti-hypoglycemic agent is used to manage and treat anaphylaxis refractory to epinephrine and to aid in passing food boluses.
• Intravenous Fluids: These are administered to maintain adequate blood circulation.

In Case of Emergency

If you are with someone experiencing an allergic reaction with signs of anaphylaxis, follow these steps:

• Call the local medical emergency number immediately.
• Check if the person is carrying an epinephrine auto-injector (EpiPen, Auvi-Q, etc.) to treat the allergic attack.
• Help the person inject the medication by pressing the auto-injector against their thigh.
• Make the person lie face up and remain still.
• Loosen their tight clothing and cover them with a blanket.
• Turn the person to the side to prevent choking if they are vomiting or bleeding from the mouth.
• Position the patient in the Trendelenburg position (lying flat on their back with legs elevated) to allow blood flow to the heart.
• If there are no signs of breathing, coughing, or movement, begin CPR (start uninterrupted chest compressions at a rate of about 100 per minute).

Correct first aid can help save a life! Know about step-by-step instructions for emergency management.

Anaphylactic shock is an extremely serious condition that can block your airways and prevent you from breathing. It can also stop your heart due to a decrease in blood pressure that prevents the heart from receiving enough oxygen. The complications of anaphylaxis include:

• Cerebral hypoxia: A condition characterized by a decrease in oxygen supply to the brain despite adequate blood flow.
• Acute renal failure: Associated with anaphylactic shock caused by diclofenac sodium.
• Fetal death: Although there is no evidence that anaphylaxis occurs in the fetus, maternal anaphylaxis can significantly increase the risk of fetal or neonatal neurological damage or death.
• Septic shock: Caused by the malfunction of the vascular system due to severe allergic reactions, resulting in blood poisoning by bacteria.
• Acute respiratory distress syndrome: A condition in which fluid collects in the air sacs of the lungs, depriving organs of oxygen.
• Abnormal coagulation profile: Anaphylaxis is a complex allergic reaction involving multiple biological systems, which can lead to disruption of coagulation systems in severe cases.
• Pulmonary edema: Histamines released during an allergic reaction cause blood vessels to expand, leading to a dangerous drop in blood pressure and fluid leakage into the lungs, resulting in swelling.
• Arrhythmia: Anaphylaxis can also cause disturbances in heart rhythm.
• Abnormal liver function: The relationship between acute liver injury and idiopathic anaphylaxis is rare, but some cases involve repeated episodes of anaphylactic shock accompanied by acute liver injury.

Homeopathy

Homeopathy works by correcting the immune responses of individuals rather than suppressing or modifying the immune system. Some individuals use homeopathic remedies for allergic reactions or allergic diseases, but there is no research showing the effectiveness of homeopathy in preventing or treating anaphylaxis. Anaphylaxis requires emergency medical treatment.

Acupuncture

Acupuncture has been used to support the immune system and to relieve symptoms of seasonal allergies. However, acupuncture should not be used to treat anaphylaxis, which requires immediate medical attention.

Traditional Chinese Medicine (TCM)

TCM has been used in China and other Asian countries for thousands of years, either as monotherapy or in combination with standard Western medical treatment. Studies suggest that an herb-based formula (FAHF-2) may be an effective approach to food allergy treatment that is not specific to any one food allergen and can potentially be used to treat multiple food allergies.

A number of general strategies and tips may help you or your child avoid anaphylaxis or improve health outcomes when a reaction happens. Some of them include:

• Anaphylaxis education: Awareness among family members and caregivers about anaphylaxis tends to decrease distress and apprehension. It instills trust in their ability to cope, not just during anaphylactic episodes but also in identifying and providing timely treatment.
• Keep a close watch on food ingredients: If you have a severe food allergy, scan food labels carefully for any harmful ingredients. Feel free to ask detailed questions about ingredients and food preparation when dining out.
• Introduce new foods to children slowly: If you or your child have had a severe allergic reaction to a food, it’s more likely that another new food will also cause problems. This might require sensitization, which means that the first few times your child tries a new food item, give it in small amounts with bites that are spaced out.
• Always wear a medical ID tag: Having a necklace or bracelet that indicates your anaphylaxis risk can help bystanders and first responders identify what’s happening in case of a reaction or emergency.
• Keep all potential treatments handy: These include an epinephrine auto-injector for nearly everyone, and possibly a chewable antihistamine and a stiff card to scrape out a bee’s stinger.
• Never share your epinephrine: You shouldn’t use your auto-injector on anyone else unless you are certain they are having an anaphylactic reaction. Doing so may put you at risk for not having this treatment available for yourself and could cause medical problems for someone who isn’t experiencing anaphylaxis.