Allergic Reaction

An allergic reaction occurs when your immune system overreacts to a normally harmless substance. Reactions can range from mild symptoms like sneezing and itching to life-threatening anaphylaxis. Recognizing the signs and knowing when to seek emergency care can be lifesaving.

Quick Facts

  • Very common condition
  • Can be life-threatening
  • Affects all ages
  • Often treatable
  • May require EpiPen

⚠️ ANAPHYLAXIS - Call 911 Immediately For:

  • Difficulty breathing or shortness of breath
  • Swelling of face, lips, tongue, or throat
  • Rapid pulse or heart palpitations
  • Dizziness, lightheadedness, or fainting
  • Severe nausea, vomiting, or abdominal cramps
  • Widespread hives or rash with other symptoms
  • Feeling of impending doom
  • Confusion or altered consciousness
  • Pale or blue skin color
  • Weak or rapid pulse

Use epinephrine auto-injector (EpiPen) if available and call 911. Anaphylaxis can be fatal within minutes.

Understanding Allergic Reactions

Allergic reactions occur when your immune system mistakenly identifies a harmless substance as a threat. This triggers the release of chemicals like histamine, causing various symptoms throughout the body. The severity and type of symptoms depend on the allergen, the route of exposure, and individual sensitivity.

Allergens can enter the body through ingestion (food), inhalation (pollen, dust), injection (insect stings, medications), or skin contact (latex, plants). Some people may have mild reactions to certain allergens while experiencing severe reactions to others.

The timing of reactions varies. Immediate reactions occur within minutes to hours, while delayed reactions may take hours to days to develop. Understanding your specific allergies and reaction patterns is crucial for effective management and prevention.

Types of Allergic Reactions

Mild Reactions

  • Sneezing
  • Runny or stuffy nose
  • Itchy, watery eyes
  • Mild skin rash
  • Localized itching
  • Minor swelling

Moderate Reactions

  • Widespread rash or hives
  • Intense itching
  • Facial swelling
  • Difficulty swallowing
  • Abdominal pain
  • Vomiting or diarrhea

Severe (Anaphylaxis)

  • Airway constriction
  • Severe swelling
  • Rapid pulse
  • Drop in blood pressure
  • Loss of consciousness
  • Cardiovascular collapse

Delayed Reactions

  • Contact dermatitis
  • Serum sickness
  • Drug rashes
  • Some food reactions
  • Hours to days later
  • May persist longer

Common Allergens

Food Allergens

  • Tree nuts: Almonds, cashews, walnuts
  • Peanuts: Actually legumes, not nuts
  • Milk: Cow's milk proteins
  • Eggs: Usually egg whites
  • Shellfish: Shrimp, lobster, crab
  • Fish: Salmon, tuna, cod
  • Wheat: Gluten proteins
  • Soy: Soybeans and products
  • Sesame: Seeds and oil

Environmental Allergens

  • Pollen: Trees, grasses, weeds
  • Dust mites: Microscopic organisms
  • Pet dander: Cats, dogs, other animals
  • Mold: Indoor and outdoor varieties
  • Cockroaches: Droppings and body parts

Contact Allergens

  • Latex: Gloves, balloons
  • Nickel: Jewelry, buckles
  • Fragrances: Perfumes, soaps
  • Poison ivy/oak: Plant oils
  • Cosmetics: Makeup, lotions
  • Cleaning products: Detergents, chemicals

Medication Allergens

  • Penicillin: And related antibiotics
  • Sulfa drugs: Various medications
  • NSAIDs: Aspirin, ibuprofen
  • Chemotherapy drugs: Cancer treatments
  • Contrast dyes: For imaging tests
  • Anesthetics: Local and general

Insect Allergens

  • Bee stings: Honeybees
  • Wasp stings: Yellow jackets, hornets
  • Fire ants: Aggressive ants
  • Mosquito bites: Saliva proteins

Symptoms by Body System

Skin Symptoms

  • Hives (urticaria) - raised, itchy welts
  • Angioedema - deep tissue swelling
  • Eczema flare-ups
  • Contact dermatitis
  • Flushing or redness
  • Itching without rash

Respiratory Symptoms

  • Wheezing
  • Coughing
  • Shortness of breath
  • Chest tightness
  • Nasal congestion
  • Throat tightness

Gastrointestinal Symptoms

Cardiovascular Symptoms

  • Rapid or weak pulse
  • Low blood pressure
  • Dizziness or fainting
  • Chest pain
  • Heart palpitations

Diagnosis and Testing

Medical History

  • Detailed symptom description
  • Timing of reactions
  • Suspected triggers
  • Family history of allergies
  • Previous reactions
  • Current medications

Allergy Testing

  • Skin prick test: Small amounts on skin
  • Intradermal test: Injection under skin
  • Patch test: For contact allergies
  • Blood tests: Specific IgE antibodies
  • Elimination diet: For food allergies
  • Challenge test: Controlled exposure

Treatment Options

Emergency Treatment

  • Epinephrine injection
  • Call 911 immediately
  • Lie flat (elevate legs)
  • Remove allergen
  • CPR if needed
  • Hospital monitoring

Medications

  • Antihistamines (Benadryl)
  • Corticosteroids
  • Bronchodilators
  • Epinephrine auto-injectors
  • Mast cell stabilizers
  • Leukotriene modifiers

Long-term Management

  • Allergen avoidance
  • Immunotherapy (allergy shots)
  • Sublingual tablets
  • Carry emergency meds
  • Medical alert bracelet
  • Action plan

Natural Approaches

  • Quercetin supplements
  • Local honey (pollen)
  • Probiotics
  • Vitamin C
  • Butterbur herb
  • Nasal irrigation

Prevention Strategies

  • Know your triggers: Keep detailed allergy diary
  • Read labels: Check all food and product ingredients
  • Communicate: Inform restaurants, schools, workplaces
  • Carry medications: Always have antihistamines and EpiPen
  • Wear medical ID: Bracelet listing allergies
  • Environmental control: HEPA filters, dust mite covers
  • Cross-contamination: Separate cooking utensils
  • Emergency plan: Written action steps
  • Regular check-ups: Monitor changing allergies
  • Educate others: Family, friends, caregivers

Living with Allergies

Daily Management

  • Check weather/pollen counts
  • Plan meals carefully
  • Carry safe snacks
  • Update emergency contacts
  • Practice using EpiPen
  • Join support groups

Travel Considerations

  • Research destination allergens
  • Pack extra medications
  • Translate allergy cards
  • Locate nearby hospitals
  • Consider travel insurance
  • Bring safe food options

When to See a Doctor

Schedule an Appointment For:

  • First-time allergic reactions
  • Worsening allergy symptoms
  • Reactions despite avoiding triggers
  • Need for allergy testing
  • Interest in immunotherapy
  • Medication side effects
  • Multiple food sensitivities
  • Chronic hives or rashes
  • Asthma with allergies

Related Conditions

Asthma

Often triggered or worsened by allergies, especially environmental allergens.

Skin Rash

Common manifestation of allergic reactions on the skin.

Seasonal Allergies

Environmental allergies causing hay fever symptoms.

Shortness of Breath

Serious allergic reactions can cause breathing difficulties.