Allergy also known as allergic diseases are a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling. Food intolerances and food poisoning are separate conditions.
Allergies can strike anytime, and anywhere. They’re one of the most common ailments, affecting millions of people each year. There are many causes of allergies, including organic and inorganic matter. Allergies develop as a result of a hypersensitive reaction by your immune system to a foreign substance, causing a range of symptoms to appear. While most allergic reactions are not severe, some people may develop life-threatening complications. Contact your doctor if you suspect being allergic to something.
Causes of Allergy
Latex
Latex allergies are among the most common types of allergies in the Western world. This kind of allergy usually develops as a reaction to previous exposures to latex. People who suffer from latex allergy are likely to experience itching, swelling, and hives in the area exposed to the material. In more severe cases, it can cause wheezing, difficulty breathing, as well as a headache. Depending on the sensitivity level, symptoms may develop a few minutes after exposure, and up to an hour afterward. Luckily, latex-free products can easily be found in most supermarkets.
Dust Mites
More than 20 million people in the US suffer from allergies due to dust mites, making this by far one of the most common causes of allergy. Dust mites are tiny, microscopic creatures that consume dead skin cells, both human and animal. Dust mites are notorious for their ability to persist even in the harshest of climates. The higher a number of dust mites, the more severe symptoms will appear. Another conditioning factor is the degree of sensitivity. Symptoms can range from mild, including coughing and itching, to more serious symptoms.
Nickel
Another frequent cause of allergy is nickel. Nickel is a metal that is most often found in different jewelry, such as earrings, bracelets, and rings. The skin around the ear can be especially sensitive to nickel, causing symptoms such as itchiness and irritation. In some cases, earrings containing nickel may lead to infections of the skin. To ensure that your earrings are nickel-free, look for a certifying engraving that can be found on the metallic earring locks. You can also consider wearing wooden jewelry, which is 100% free of nickel. To test for symptoms, rub your earring on the skin of ear and look for red patches of skin.
Cockroaches
As terrifying as it may sound, cockroaches are one of the most probable causes of allergic symptoms. Cockroaches can trigger symptoms in many people due to a unique protein found in their excrement and saliva. When it enters contact with humans, it can cause symptoms affecting the skin, lungs, and eyes. In some cases, cockroaches can even trigger an asthma attack. To reduce the risk of a cockroach infestation, make sure there is no food lying around the house, and remove any excess moisture from walls and the floor. If you still report symptoms, contact an exterminator.
Fragrances
Many people enjoy wearing alluring fragrances to work or just for a night of partying. Perfumes and colognes have been an important part of cosmetic history for many centuries already. These aromatic substances are made with a variety of ingredients, some natural and some artificial. Most people can wear them just fine, but a few may experience an allergic reaction. You may experience rashes, swelling, and itchiness on the skin if you are allergic to fragrances. Soap, shampoo, and dental products may provoke similar symptoms. You can always shop for products that are free from irritating substances.
Certain Foods
Many people suffer from food allergies: in fact, you may be one of more than 15 million Americans that report some food or drink allergy. Some of the most common forms of food allergy include nuts, milk, soy, fish, and onions. You are considered to have a food allergy if your body’s immune system reacts aggressively to the presence of certain foods. Depending on the person, symptoms can range from mild to severe. Some of the most frequent symptoms include a cough, diarrhea, vomiting and stomach ache. Severe symptoms can be life-threatening, so seek medical attention if you experience difficulty breathing, dizziness, or severe pain.
Mold
If you live in a damp, wet environment that experiences frequent rainfall and humidity, you may be at risk of developing household mold. Mold can grow nearly anywhere as long as the bacteria that cause it can thrive. Mold is classified as a fungus, and it can reproduce and spread. If mold particles enter the nasal passage, they can provoke allergic symptoms to develop, including irritation of the eyes, cough, as well as asthma attacks. To reduce the presence of mold, ensure that surfaces are kept dry and free from moisture.
Quaternium
In most cases, symptoms related to allergies are caused by organic matter, such as pollen or animal fur. While these are often the most common trigger of allergies, they aren’t the only ones. Many human-made and artificial products can also cause an allergic reaction to take place, including many cosmetics. That’s why women – who wear the most amount of makeup – are more likely to experience these symptoms. One of the most common allergens is quaternium 15, which is a type of preservative abundantly found in different cosmetic products. Shampoo, nail polish, and sunscreen are just a few of the products containing it.
Pollen
Pollen allergy is one of the most common forms of allergy in the USA. It is caused by an allergic reaction that takes place inside the body when it becomes in contact with pollen. Pollen is a powder that is produced by different organisms, including trees, flowers, as well as weeds. Many people suffer from pollen allergies, which is why spring is also known as the allergy season. If pollen finds its way into your nasal passage, throat, or lungs, it may trigger an allergic reaction. Some of the main symptoms include coughing, swelling, itching, and even pain.
Symptoms of Allergy
Symptoms of a food allergy may include
- Tingling in the mouth
- Swelling of the lips, tongue, face, or throat
- Hives
- Stomachache
- Anaphylaxis (a severe, life-threatening allergic reaction)
An insect sting allergy may cause
- A large area of swelling at the site of the sting
- Wheezing, cough, chest tightness, or shortness of breath
- Itching or hives all over your body
- Anaphylaxis
A reaction to medications may lead to
- Itchy skin
- Hives (small red spots especially on the chest, back, or abdomen) or other rashes
- Facial swelling
- Wheezing
- Anaphylaxis
Airborne allergies can cause allergic rhinitis (hay fever), which is characterized by
- Sneezing
- Runny, stuffy nose
- Watery, red, or swollen eyes
- Coughing
- Itching of the nose, eyes, or roof of the mouth
Diagnosis of Allergy
Finding out exactly what’s causing your allergies is an important step to ensuring you receive effective allergy treatment. If you think you have allergies, your doctor will probably recommend that you see an allergy specialist. Your allergist may perform a physical exam, look at your medical history, and perform the following tests:
- Skin test – In this test, concentrated drops of various allergens are pricked or scratched on the surface of the skin. If you’re allergic to any of these allergens, you’ll develop a red bump (hive), redness, and swelling at the test spot. Doctors sometimes recommend a second type of test, in which a small amount of the allergen is injected into the skin of the arm. Certain medicines may interfere with the interpretation of allergy skin tests, so be sure to tell your healthcare provider about any prescription or over-the-counter (OTC) drugs you’re taking.
- Blood test – A test known as the radioallergosorbent test (RAST) measures the amount of allergy-causing antibodies in your bloodstream (known as IgE antibodies).T he RAST test can help doctors measure your immune system’s response to a particular allergen.
- IgE Test – The test measures the concentration of specific IgE antibodies in the blood. Quantitative IgE test results increase the possibility of ranking how different substances may affect symptoms. A rule of thumb is that the higher the IgE antibody value, the greater the likelihood of symptoms. Allergens found at low levels that today do not result in symptoms can nevertheless help predict future symptom development. The quantitative allergy blood result can help determine what a patient is allergic to, help predict and follow the disease development, estimate the risk of a severe reaction, and explain cross-reactivity.
- A low total IgE level is not adequate to rule out sensitization to commonly inhaled allergens. Statistical methods, such as ROC curves, predictive value calculations, and likelihood ratios have been used to examine the relationship of various testing methods to each other. These methods have shown that patients with a high total IgE have a high probability of allergic sensitization, but further investigation with allergy tests for specific IgE antibodies for a carefully chosen of allergens is often warranted.
- Laboratory methods to measure specific IgE antibodies for allergy testing include enzyme-linked immunosorbent assay (ELISA, or EIA), radioallergosorbent test (RAST) and fluorescent enzyme immunoassay (FEIA).
Patch testing
Allergy type | United States | United Kingdom |
---|---|---|
Allergic rhinitis | 35.9 million (about 11% of the population) | 3.3 million (about 5.5% of the population) |
Asthma | 10 million have allergic asthma (about 3% of the population). The prevalence of asthma increased 75% from 1980 to 1994. Asthma prevalence is 39% higher in African Americans than in Europeans. | 5.7 million (about 9.4%). In six- and seven-year-olds asthma increased from 18.4% to 20.9% over five years, during the same time the rate decreased from 31% to 24.7% in 13- to 14-year-olds. |
Atopic eczema | About 9% of the population. Between 1960 and 1990 prevalence has increased from 3% to 10% in children. | 5.8 million (about 1% severe). |
Anaphylaxis | At least 40 deaths per year due to insect venom. About 400 deaths due to penicillin anaphylaxis. About 220 cases of anaphylaxis and 3 deaths per year are due to latex allergy. An estimated 150 people die annually from anaphylaxis due to food allergy. | Between 1999 and 2006, 48 deaths occurred in people ranging from five months to 85 years old. |
Insect venom | Around 15% of adults have mild, localized allergic reactions. Systemic reactions occur in 3% of adults and less than 1% of children. | Unknown |
Drug allergies | Anaphylactic reactions to penicillin cause 400 deaths per year. | Unknown |
Food allergies | About 6% of US children under age 3 and 3.5–4% of the overall US population. Peanut and/or tree nut (e.g. walnut) allergy affects about three million Americans, or 1.1% of the population. | 5–7% of infants and 1–2% of adults. A 117.3% increase in peanut allergies was observed from 2001 to 2005, an estimated 25,700 people in England are affected. |
Multiple allergies (Asthma, eczema and allergic rhinitis together) | Unknown | 2.3 million (about 3.7%), prevalence has increased by 48.9% between 2001 and 2005. |
Urticaria, angio courses Flush, pruritus Oral allergy syndrome (local itching and tingling and/or edema of lips, tongue, palate, and pharynx) |
IgE-mediated mast cell/basophil degranulation | Acute onset after food ingestion (minutes-hours) | In infants and adults, may resolve with age Appears mainly in adults with established pollen allergies, long-lived, boosted by pollen contact |
|
Contact urticaria | After direct skin contact | In infants and adults | ||
Atopic dermatitis Protein contact dermatitis |
T cell-mediated (with or without the involvement of IgE) | Delayed type reaction > 24 hours after food ingestion | In infants and adults | |
Respiratory tract | Laryngeal and/or pharyngeal edema Hoarseness, cough |
IgE-mediated mast cell/basophil degranulation | Acute onset after food ingestion (minutes-hours) | In infants and adults |
Rhinoconjunctivitis Bronchial asthma |
T cell-mediated (with or without the involvement of IgE) | Delayed type reaction > 24 hours after food ingestion | In infants and adults Baker’s asthma in adults |
|
Gastrointestinal tract | Colitis Diarrhea Gastroenteritis Anorexia Nausea, vomiting Abdominal pain Flatulence Abdominal distension |
IgE-mediated mast cell/basophil degranulation | Acute onset after food ingestion (minutes-hours) | In infants and adults |
Gastroenteritis | T cell-mediated (with or without involvement of IgE) | Delayed type reaction > 24 hours after food ingestion, increased pro-inflammatory cytokine responses | In infants and adults, may resolve with age | |
Eosinophilic gastroenteritis Eosinophilic esophagitis |
Eosinophilic gastroenteritis | Eosinophil-activation by cytokines | In infants and adults | |
Cardiovascular system | Tachycardia Hypotension Vascular collapse Anaphylactic shock Cardiac dysrhythmia |
IgE-mediated mast cell/basophil degranulation | Acute onset after food ingestion (minutes-hours) | In infants and adults |
Nervous system | Irritability Anxiety |
IgE-mediated mast cell/basophil degranulation? | Acute onset after food ingestion (minutes-hours) | In infants and adults |
Confusion | and/or | and/or | ||
Loss of consciousness | T cell-mediated (with or without involvement of IgE)? | Delayed type reaction > 24 hours after food ingestion |
Treatment of Allergy
- If your allergies are severe enough to significantly interfere with your quality of life, it’s a good idea to see a doctor in order to identify what you are allergic to and to gain access to the full range of prescription options.
- If your allergies are less severe or merely annoying, you may be able to find an effective over-the-counter (OTC) treatment. A pharmacist may be able to help you choose the best option based on your symptoms.
- Certain medications can help reduce your immune system’s reaction to allergens, which eases symptoms. Allergy drugs come in both OTC and prescription forms. They can be taken as liquids, pills, nasal sprays, or eye drops.
Common allergy medicines include
These drugs work by blocking the effects of histamine (a chemical in the body that can cause allergy symptoms). They’re sometimes combined with other types of drugs.
Examples of antihistamines include
- Allegra (fexofenadine)
- Astelin or Astepro (azelastine)
- Benadryl (diphenhydramine)
- Clarinex (desloratadine)
- Claritin or Alavert (loratadine)
- Dimetane (brompheniramine)
- Emadine (emedastine)
- Livostin (levocabastine)
- Optivar (azelastine)
- Palgic (carbinoxamine)
- Xyzal (levocetirizine)
- Tavist (clemastine)
- Zyrtec (cetirizine)
Decongestants
These medicines relieve congestion by shrinking swollen nasal tissues and blood vessels, and are often prescribed along with antihistamines.
Examples of decongestants include:
- Sudafed (pseudoephedrine)
- Neo-Synephrine or Afrin (oxymetazoline)
- Some forms of Visine eye drops
Allegra-D
- (fexofenadine and pseudoephedrine), Zyrtec-D (cetirizine and pseudoephedrine), and Claritin-D (loratadine and pseudoephedrine) contain both a decongestant and an antihistamine.
Mast cell stabilizers
- These medications block the release of immune system chemicals that play a role in allergic reactions.
- Examples of mast cell stabilizers include:
- Crolom (cromolyn)
- Alomide (lodoxamide)
- Alocril (nedocromil)
Steroids
These drugs can help reduce inflammation and swelling.
Common steroids for allergies include:
- Flonase or Veramyst (fluticasone)
- Nasacort (triamcinolone)
- Qnasl (beclomethasone)
- Nasonex (mometasone)
- Omnaris (ciclesonide)
- Prednisone
Asthma medications
- Severe lethargy
- Sometimes therapies typically used for asthma — such as leukotriene receptor antagonists (LTRAs), bronchodilators, and certain steroids — are prescribed to help treat allergy symptoms.
Emergency epinephrine
- This medicine is used to treat anaphylaxis (a severe, life-threatening allergic reaction) until emergency treatment is administered.
- Epinephrine is administered as a shot.
Allergy Shots
- Allergy shots — also known as allergen immunotherapy — can be given to reduce sensitivity to certain allergens and improve symptoms.
- This therapy involves injecting small amounts of allergen extracts into your body to stimulate your immune system, without causing an allergic reaction. Your doctor will increase the allergen dose over time.
- The shots work like a vaccine, as your body develops immunity and tolerance to particular allergens after being exposed to them.
- They’re typically given over the course of three to five years.
Both adults and children can receive allergy shots, but they’re usually not recommended for children under age 5.
Allergy Drops
- Allergy drops for the mouth — known as sublingual immunotherapy — are a newer way to acclimate the body to allergens without injections.
- In this therapy, a small dose of an allergen is delivered under the tongue to boost tolerance and immunity. The therapy is typically taken at home.
- This treatment is gaining popularity in the United States, but it’s still not considered an established therapy by the Food and Drug Administration (FDA).
Allergen immunotherapy
- It is useful for environmental allergies, allergies to insect bites, and asthma. Its benefit for food allergies is unclear and thus not recommended. Immunotherapy involves exposing people to larger and larger amounts of allergen in an effort to change the immune system’s response.
- Meta-analyses have found that injections of allergens under the skin is effective in the treatment in allergic rhinitis in childrenand in asthma. The benefits may last for years after treatment is stopped. It is generally safe and effective for allergic rhinitis and conjunctivitis, allergic forms of asthma, and stinging insects.
- The evidence also supports the use of sublingual immunotherapy for rhinitis and asthma but it is less strong. For seasonal allergies the benefit is small. In this form, the allergen is given under the tongue and people often prefer it to injections. Immunotherapy is not recommended as a stand-alone treatment for asthma.
Treatment | Type of drug | Mechanism | Trial examples | (Preliminary) results |
---|---|---|---|---|
ANB020 | IL-33-specific antibody | Blocks IL-33-induced signalling, which normally favours TH2 cell-mediated allergic responses | Phase I | NA |
Reslizumab | Humanized mouse monoclonal antibody | Binds free IL-5, preventing IL-5 receptor activation | Off label[rx] | No clinical effect in EoE, though decrease in eosinophilic infiltration of oesophagus |
Mepolizumab | Humanized mouse monoclonal antibody | Binds free IL-5, preventing IL-5 receptor activation | Off label[rx] | Decrease in eosinophilic infiltration of oesophagus in EoE |
Omalizumab | Humanized mouse monoclonal antibody | Binds Fc region of IgE, blocking FceRI binding | Phase I and II (see main text and REFS rx–rx) | Reduces allergen-mediated mast cell degranulation; FceRI signal blockade blunts TH2 cell-mediated response; mitigates allergen side effects and allows rapid escalation of OIT dose |
OIT for treatment | Allergen taken orally | Potentially functions via expansion of allergen-specific CD4+FOXP3+ Tregcell population | Egg (CoFAR study)[rx] | 75% desensitization and 28% sustained unresponsiveness |
OIT for prevention | Allergen taken orally | Potentially functions via expansion of allergen-specific CD4+FOXP3+ Tregcell population | Peanut (LEAP study)[rx] | 13.7% of SPT-negative infants developed peanut allergy in the avoidance group versus 1.9% in the consumption group |
SLIT | Allergen administered sublingually | Potentially functions via expansion of allergen-specific CD4+FOXP3+ Tregcell population | Hazelnut[rx]and peanut127 | 45% of the treatment group reached the highest dose of hazelnut (20 g), versus 9% of the placebo group; modest desensitization to peanut in most test subjects versus placebo |
EPIT | Allergen absorbed through skin | Potentially functions via expansion of allergen-specific CD4+FOXP3+ Tregcell population | Phase I (for milk)[rx] | Abstracts report promising increases in dose threshold for food allergic symptoms |
EMP-123 | Recombinant Ara h 1, Ara h 2 and Ara h 3 | Rectal administration to induce mucosal tolerance | Phase I (REF. rx) | Increased food allergic reactions with drug |
Peanut vaccine | Ara h 1, Ara h 2 and Ara h 3 | Presentation of peanut protein without inflammation induces tolerance | Phase I and preclinical | NA |
CoFAR, Consortium for Food Allergy Research; EoE, eosinophilic oesophagitis; EPIT, epicutaneous immunotherapy; IL, interleukin; LEAP, Learning Early About Peanut Allergy; NA, not applicable; OIT, oral immunotherapy; SLIT, sublingual immunotherapy; SPT, skin prick test; TH2, T helper 2; Treg cell, regulatory T cell
Allergen Avoidance
- One of the most important steps you can take to reduce your symptoms is to avoid allergy triggers.
- Allergic reactions can still occur, even if you’re diligent about staying away from known allergens.
Allergy Medicine While Pregnant
- Certain allergy medicines are safe to take during pregnancy, while others aren’t.
- Talk to your doctor about the risks and benefits of taking these drugs while you’re pregnant.
- Your healthcare provider can help you choose the safest treatment option for you and your baby.
Home Remedies for Allergy
You can reduce many allergy symptoms at home by taking the following steps
Performing saline nasal irrigation
- With this method, you rinse out your sinuses with a saltwater solution to reduce congestion.
You can use a or a special squeeze bottle. Be sure to follow all usage and cleaning instructions provided by the manufacturer.
Washing bedding frequently
- You can greatly reduce your exposure to dust mites and pet dander by washing bedding and other items often. Be sure to use hot water.
Consuming local honey
- There’s little scientific evidence to back up this remedy, but some people report fewer allergy symptoms when they eat honey produced by bees in their region.
Using a high-efficiency particulate air (HEPA) filter
- These filters trap allergens and other airborne irritants, which may reduce your symptoms.
Replacing carpeting with hard flooring
- This makes it easier to keep surfaces clean and free of possible allergens.
Taking herbal or other dietary supplements
- Certain herbs, like butterbur extract, may reduce allergy symptoms in some people, but there is little scientific evidence to support these claims.
- Talk to your doctor about the risks and benefits of any dietary supplement before taking it.
Home Remedies for Allergy
Spring fever
Neti pots
Saline spray
Local honey
HEPA filter
Steam
Tea