Symptoms
Allergy symptoms vary depending on the allergen and the individual. Common symptoms include:
Respiratory: Sneezing, runny or stuffy nose, itchy nose, postnasal drip, sore throat, coughing, wheezing, shortness of breath.
Skin: Itchy skin, hives (urticaria), eczema, rash.
Eyes: Itchy, watery, red, swollen eyes.
Digestive: Nausea, vomiting, diarrhea, abdominal pain.
Severe (Anaphylaxis): Difficulty breathing, wheezing, throat swelling, dizziness, lightheadedness, loss of consciousness.
Causes
Allergies are caused by a complex interplay of genetic predisposition and environmental factors. While the exact reasons why some people develop allergies and others don't are still being researched, key contributing factors include:
Genetic Predisposition: Allergies tend to run in families, suggesting a genetic component.
Environmental Exposure: Early childhood exposure to certain allergens may increase the risk of developing allergies.
Immune System Development: The way the immune system develops in early life can influence the likelihood of allergies. The "hygiene hypothesis" suggests that reduced exposure to microbes in early childhood can lead to an increased risk of allergies.
Specific Allergens: Exposure to specific allergens triggers the allergic reaction in sensitized individuals.
Medicine Used
A variety of medications are used to manage allergy symptoms. The specific medication depends on the type and severity of the allergy. Common medications include:
Antihistamines: Block the effects of histamine, relieving symptoms like sneezing, itching, and runny nose. Examples include cetirizine (Zyrtec), loratadine (Claritin), fexofenadine (Allegra), and diphenhydramine (Benadryl).
Decongestants: Help to relieve nasal congestion by narrowing blood vessels in the nasal passages. Examples include pseudoephedrine (Sudafed) and phenylephrine.
Nasal Corticosteroids: Reduce inflammation in the nasal passages. Examples include fluticasone (Flonase) and budesonide (Rhinocort).
Eye Drops: Antihistamine or steroid eye drops can relieve itchy, watery eyes.
Leukotriene Modifiers: Block the effects of leukotrienes, which contribute to allergy symptoms. Montelukast (Singulair) is an example.
Epinephrine (EpiPen): Used to treat severe allergic reactions (anaphylaxis).
Allergy Shots (Immunotherapy): A series of injections containing small amounts of the allergen to gradually desensitize the immune system.
Is Communicable
Allergies are not communicable. They are not caused by an infection and cannot be spread from person to person. Allergies are an immune system response to a specific substance.
Precautions
Avoidance: The most effective precaution is to avoid exposure to known allergens.
Read Labels: Carefully read food and product labels to identify potential allergens.
Allergy-Proofing: Reduce allergen exposure in the home by using air purifiers, hypoallergenic bedding, and vacuuming regularly.
Medical Alert: Wear a medical alert bracelet or necklace to indicate known allergies.
Carry Medication: If prescribed, always carry emergency medication like an epinephrine auto-injector (EpiPen).
Inform Others: Inform family, friends, and caregivers about allergies and how to respond to a reaction.
Pre-emptive Medication: Take prescribed medications (antihistamines, etc.) before potential allergen exposure if possible.
How long does an outbreak last?
The duration of an allergic reaction varies widely depending on the allergen, the severity of the reaction, and the individual's response.
Mild reactions: Symptoms may resolve within a few hours to a day with or without medication.
Moderate reactions: Symptoms might last several days to a week, requiring medication to manage them.
Seasonal allergies: Symptoms can persist for weeks or months during the pollen season.
Chronic allergies: Such as those to dust mites or pet dander, symptoms can be ongoing and require continuous management.
Anaphylaxis: This is a severe reaction that requires immediate treatment and can be life-threatening if not treated promptly. The reaction itself can occur rapidly, within minutes of exposure.
How is it diagnosed?
Allergies are diagnosed through a combination of medical history, physical examination, and allergy testing:
Medical History: The doctor will ask about symptoms, potential allergens, family history of allergies, and other relevant medical information.
Physical Examination: A physical exam may reveal signs of allergies, such as skin rashes, nasal congestion, or wheezing.
Skin Prick Test: Small amounts of potential allergens are pricked onto the skin. A raised, itchy bump (wheal) indicates an allergy.
Intradermal Skin Test: A small amount of allergen is injected under the skin.
Blood Test (Specific IgE Antibody Test): Measures the amount of IgE antibodies specific to certain allergens in the blood.
Elimination Diet: For suspected food allergies, certain foods are eliminated from the diet to see if symptoms improve. Then, the foods are reintroduced one at a time to identify the culprit allergen.
Timeline of Symptoms
The timeline of allergy symptoms can vary significantly depending on the allergen and the type of reaction:
Immediate Reactions: Some reactions, such as those to insect stings or certain foods, can occur within minutes of exposure. Symptoms may include hives, itching, swelling, and difficulty breathing.
Delayed Reactions: Other reactions may take hours or even days to develop. For example, contact dermatitis from poison ivy may not appear for 12-48 hours after exposure.
Seasonal Allergies: Symptoms typically appear during specific times of the year, such as spring (pollen) or fall (ragweed). Symptoms worsen during peak allergen levels and improve when levels decrease.
Chronic Allergies: With chronic allergies like dust mite or pet dander allergies, symptoms may be present year-round, with fluctuations depending on exposure levels.
Important Considerations
Anaphylaxis: Be aware of the signs and symptoms of anaphylaxis and know how to use an epinephrine auto-injector (EpiPen) if prescribed. Anaphylaxis is a medical emergency.
Cross-Reactivity: Be aware of potential cross-reactivity between allergens. For example, people with pollen allergies may also react to certain fruits and vegetables.
Allergy Management Plan: Develop an allergy management plan with your doctor, including strategies for avoiding allergens, managing symptoms, and treating allergic reactions.
Regular Follow-Up: Schedule regular follow-up appointments with your allergist to monitor your allergies and adjust your treatment plan as needed.
Impact on Quality of Life: Allergies can significantly impact quality of life. Seek medical help to manage symptoms effectively.
Infants and Children: Allergy symptoms can present differently in infants and children. It's essential to work with a pediatrician or allergist to diagnose and manage allergies in young children.