What determines which symptoms an allergen will cause?

What determines which symptoms an allergen will cause?

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Allergies result in many different symptoms such as sneezing, runny nose, itchy eyes, coughing, rashes, swelling of the face, stomach pain, vomiting, dry skin, anaphylaxis, etc.

An allergen can cause different symptoms for different people who are allergic to it… and different allergens can cause completely different symptoms for the same person. What characteristics of an allergen and/or the person determine what symptoms will arise?

Before having a food allergy reaction, a sensitive child must have been exposed to the food at least once before, or could also be sensitized through breast milk. It is the second time your child eats the food that the allergic symptoms happen. At that time, when IgE antibodies react with the food, histamines are released, which can cause your child to experience hives, asthma, itching in the mouth, trouble breathing, stomach pains, vomiting, and/or diarrhea.

Food allergy causes an immune system response, causing symptoms in your child that range from uncomfortable to life-threatening. Food intolerance does not affect the immune system, although some symptoms may be the same as in food allergy.

Allergic Rhinitis Symptoms

Symptoms Of Allergic Rhinitis

The most common symptoms of allergic rhinitis or hay fever usually include:

  • Stuffy nose (due to blockage or congestion)
  • A runny nose
  • Sneezing
  • A cough
  • Inflammation of the mucous membrane
  • Itchy eyes, throat, mouth or skin
  • Redness
  • Swollen eyelids
  • Swelling of tissues
  • Fatigue (due to poor sleep)

Classic Presentation

Based on his experience with over 2,500 patients, leading expert Scott Commins, MD, PhD has identified seven characteristics that occur in 85% of patients with alpha-gal syndrome:

(I) Onset in adult life after eating mammalian meat without problems for many years

(II) Reactions range from pruritus, localized hives or angioedema to anaphylaxis

(III) Patients can report strictly gastrointestinal symptoms (diarrhea, abdominal cramping, emesis) almost to the exclusion of cutaneous, cardiovascular, or respiratory manifestations

(IV) Reactions start 3–8 hours after eating non-primate mammalian meat (or consumption of dairy, gelatin, or other mammalian-derived products)

(V) Positive testing for alpha-gal IgE (>0.1 IU/mL)

(VI) Improvement of symptoms when adhering to an appropriate avoidance diet

(VII) Description of large local reactions to tick or other arthropod bites, often including report of an ‘index’ bite that behaved differently than prior bites (57)

Onset in adulthood

GI symptoms in isolation of other symptoms

Delayed reactions, often striking in the middle of the night

Large, itchy tick bite

Symptoms improve after a change of diet

Exceptions to this classic presentation include:

  • A significant number of pediatric cases occur (91), especially in some cohorts (84). Pediatric cases may report:
    • Reactions tend to occur after ingestion of a limited number of foods (57)
    • Primary symptoms are gastrointestinal (57)
    • A strong association of reactions with physical activity, such as sports (57)

    …we have seen many children who had been diagnosed with idiopathic urticaria/anaphylaxis, or who had been specifically told that the reactions were not a result of food allergy, who had IgE antibodies to a-Gal and, in retrospect, a history consistent with delayed reactions to mammalian meat (103).

    Pediatric cases: GI symptoms

    Children often primarily report GI symptoms

    Pediatric cases: sports

    With children, there can be a strong association between reactions and sports

    Allergy: Symptoms & Signs

    Allergies are exaggerated immune responses to environmental triggers known as allergens. Allergies are very common, and about 50 million people in North America suffer from allergies. One of the most common forms of allergy is allergic rhinitis ("hay fever"), which produces symptoms like

    The symptoms of hay fever can, in turn, lead to fatigue and lethargy. Other types of allergic reactions can involve the skin (hives and itching). Anaphylactic shock is a severe form of allergic reaction that can be life-threatening. In anaphylactic shock, there is swelling of the throat and difficulty breathing. Asthma is also related to allergies in many cases.

    The symptoms of allergies can sometimes resemble those of other conditions. The common cold and the flu can cause respiratory symptoms similar to allergies. Typically, allergy symptoms are associated with a specific time of year or exposure to an allergen.

    Causes of allergies

    Allergies result from an inappropriate or misguided reaction to foreign substances (usually harmless substances). Allergens are the substances that trigger allergies. Pollens are the allergens that cause hay fever, one of the most common types of allergic reaction.

    How Allergies Work

    A properly functioning immune system is a well-trained and disciplined biological warfare unit for the body. The immune system is really quite amazing. It is able to identify and destroy many foreign invaders. The immune system can also identify cells that are infected internally with viruses, as well as many cells that are on their way to becoming tumors. It does all of this work so the body remains healthy.

    As amazing as the immune system is, it sometimes makes mistakes. Allergies are the result of a hypersensitive immune system. The allergic immune system misidentifies an otherwise innocuous substance as harmful, and then attacks the substance with a ferocity far greater than required. The problems this attack can cause range from mildly inconvenient and uncomfortable to the total failure of the organism the immune system is supposed to be protecting.

    In this article, we'll examine the most established school of thought on what makes up the condition referred to as an allergy. A defining premise of this school of thought is that allergic symptoms are always triggered by a protein.

    If you have allergies, chances are that you inherited this trait. If you have read How Your Immune System Works, you know about lymphocytes, also known as white blood cells. Lymphocytes are a fundamental component of the immune system, and when they make a mistake it can create an allergic response.

    There are two types of lymphocytes:

    Both types help guard your body against foreign substances such as invading bacteria, viruses and toxins. They move freely through and among the tissues of the body, travel through the walls of blood vessels, and move between the various lymph nodes and lymph channels. B-cells and T-cells go everywhere.

    Lymphocytes act like traveling customs agents. Everywhere they go, they are busy checking the passports of every cell they encounter. Whenever they discover a cell that seems threatening, they immediately begin countermeasures against it. The biochemical process behind these countermeasures is amazing!

    Allergic Threats

    When a lymphocyte encounters a particle or cell with surface marker molecules that identify it as a foreign invader, it performs a microscopic version of taking fingerprints and mug shots of the invader. Because these foreign invaders cause the production of antibodies, they are called antibody generators, or antigens. After a B-cell identifies an antigen, it will make its way back to a lymph node, change into a plasma cell and produce antibodies specifically engineered to fight that particular threat.

    There are five basic types of antibodies, called immunoglobulins, or Igs. Each is classified by type with a letter suffix:

    The Ig responsible for allergic reactions is IgE.

    IgE antibodies are present in everyone -- but remember those immune response genes mentioned previously? In a properly functioning immune system, the genetic code contains enough information to enable the lymphocytes to distinguish between threatening and non-threatening proteins. In an allergic person's immune system, the lymphocytes can't tell that the protein ingested as part of a meal containing shellfish isn't invading the body. The B-cells of an allergic person -- "misinformed" at the genetic level -- cause the production of large quantities of IgE antibodies that attach themselves to mast cells and basophils throughout the body. This is known as the sensitizing exposure.

    • Allergen - an allergy-causing substance
    • Antibody - a B-cell-produced protein molecule made in response to, and reactive with, a specific antigen
    • Antigen - a substance capable of causing the production of antibodies and then reacting specifically with these antibodies
    • B-cell (B-lymphocyte) - a type of white blood cell capable of producing antibodies
    • Basophil - a white blood cell containing histamine and other allergy mediators
    • Histamine - a chemical present mainly in mast cells that, when released, causes many of the symptoms of allergy
    • IgE - the type of antibody most instrumental in allergic reactions
    • Lymph nodes - small organs within the lymph system located at the intersections of lymph channels
    • Lymphocyte - a type of white blood cell instrumental in antibody production
    • Mast cell - a type of cell containing histamine and other allergy mediators instrumental in the allergic response

    Although mast cells are found in connective tissue and basophils are a type of white blood cell, they have one thing in common to the allergy sufferer. They contain histamine, an important weapon in the body's arsenal for fighting infection. Unfortunately, when released into the body inappropriately or in too high a quantity, histamine is a potentially devastating substance.

    The Allergic Cascade

    It takes between a week and 10 days of sensitizing exposure for the mast cells and basophils to become primed with IgE antibodies. Then, if the allergen comes along again, it triggers a destructive domino effect within the system called the allergic cascade.

    Whether it's a protein molecule on a ragweed pollen particle that has been inhaled, or the injected protein in the venom of a wasp, the same sequence of events takes place:

    • The IgE antibodies bound to the surfaces of basophils and mast cells recognize the protein surface markers of the allergen.
    • The IgE antibodies react by binding to the protein surface markers while remaining attached to the mast cells or basophils.
    • This binding alerts a group of special proteins called the complement complex that circulates in the blood.

    There are about 20 proteins in this family of proteins, at least nine of which are involved in the allergic-response mechanism. After the IgE antibody (which is already attached to a mast cell or basophil) encounters and binds to its specific allergen, the first complement protein attaches itself to the site. This alerts the next complement protein in the sequence, which joins and alerts the next, and so on. When the string is complete, the offending cell is destroyed. This is fine in a normal immune system, as Ig antibodies latch onto surface markers of disease cells and cause their destruction. But in an allergic episode, the cells involved are mast cells and basophils.

    When mast cells and basophils are destroyed, their stores of histamine and other allergy mediators are released into the surrounding tissues and blood. This causes dilation of surface blood vessels and a subsequent drop in blood pressure. The spaces between surrounding cells fill with fluid. Depending on the allergen or the part of the body involved, this brings on the various allergy symptoms, some of the most common being:

    • Itching (body, eyes, nose)
    • Hives
    • Sneezing
    • Wheezing
    • Nausea
    • Diarrhea
    • Vomiting

    Cross Reactivity

    Although the exact mechanism isn't yet understood, allergy sufferers sometimes find that once they have become sensitized to certain allergens, they also exhibit allergic symptoms when exposed to related substances. For example, if you have an allergic reaction to honeybee venom, you might also test positive for hypersensitivity to all other types of bee venom.

    Systemic Reactions

    Some allergic people become sensitized to proteins in such things as ragweed pollen, latex, certain foods, and drugs like penicillin. With these allergies, the reaction can involve the entire body. This is called a systemic reaction, and is what your doctor is watching for when you are asked to wait around for a while after an injection. In a systemic reaction, the release of allergy mediators (chief among them being histamine) causes capillaries all over the body to dilate. If this proceeds to the point of danger, it is known as anaphylaxis. If it proceeds even further, the victim passes into anaphylactic shock. See the next page to learn more.

    The exposure-reaction time can vary depending on your body (how well you handle the exposure) and the allergen you were exposed to. In a mild case, you may only have mild itching or swelling. In a severe reaction, after exposure to the triggering antigen, you may suddenly develop hives over large areas of your body and begin having breathing difficulties (this is accompanied by a rapid and severe drop in blood pressure). Also, in a severe reaction, thinking becomes muddled as the brain and other vital organs become oxygen-starved. The brain and kidneys are especially vulnerable in this type of reaction and may be permanently damaged even if the victim survives.

    To make matters worse, cell fluids dumped into the tissues of the throat can cause the throat to swell shut, leading to anaphylactic shock and death in as little as three or four minutes after exposure to the antigen or the onset of symptoms. Hundreds of people die annually from anaphylactic shock in the United States alone.

    Currently, the only effective treatment for anaphylaxis is an intramuscular injection of epinephrine, a hormone the body produces naturally in the adrenal glands. Epinephrine counteracts the symptoms of anaphylaxis by constricting the blood vessels and opening the airways. The down side is that its effects last only 10 to 20 minutes per injection, it has some potentially serious side effects, and it must be administered correctly at or before the onset of symptoms to be effective.

    Allergy Types, Tests and Treatment

    The list of possible allergens may be limited only by the number of protein molecules in existence. However, some do turn up more than others. Many people suffer from seasonal, respiratory allergies, usually in the spring or fall and caused by pollen, mold and dust. Some people suffer from food allergies. Common allergenic foods are peanuts and shellfish. Of injected allergens, penicillin and insect venom are common offenders.

    Allergists use a variety of diagnostic techniques to determine if a person is allergic. Unfortunately, the safest and often the most effective tests are not completely reliable by themselves in identifying if a substance is the cause of a patient's symptoms.

    The most common test, the scratch test, consists of applying a diluted extract of the possible allergen to the back or arm, and then scratching the skin with a needle. If the patient develops a certain degree of swelling or redness in the scratched area, the existence of IgE antibodies to that allergen is indicated. Blood tests are another avenue of diagnostics, especially in small children. With small children, the scratch test is used less often because the possible allergens used in the test may actually trigger a reaction in a child who has not been exposed to that substance before. Neither the scratch test nor the blood test is 100 percent accurate, but the results, taken together with a patient's medical history, can help the doctor or allergist with a diagnosis and treatment plan.

    There are three techniques commonly offered by doctors to help allergy sufferers:

    Many allergens, once identified, can simply be avoided. If you know you're allergic to shellfish, you don't eat it. Pet allergies can be handled sometimes by keeping the pet outside.

    Unfortunately, many allergens -- like pollen, mold and dust -- are very difficult, if not impossible, to avoid. These can often be managed by using medications such as antihistamines, decongestants, cromolyn sodium, corticosteroids and, in the case of anaphylaxis, epinephrine.

    Immunotherapy is expensive, time consuming and not without risk. But it is often the only hope a person has for leading a normal life. It consists of a series of injections of the offending allergen, beginning with a very weak dilution and gradually building in strength to a maintenance dose that may be continued over time. The injections help the immune system to produce fewer IgE antibodies, while also stimulating the production of a blocking antibody called IgG. This works to varying degrees with many allergies, but some cannot be treated this way.

    As with all medical discomforts and problems, you should seek the advice of your doctor or allergist if you suspect you are allergic to something.

    For more information on allergies and related topics, check out the links on the next page.

    Fish Allergy

    Do you suspect that you’ve recently developed a fish allergy? Unlike other food allergies, which are typically first observed in babies and young children, an allergy to fish may not become apparent until adulthood in one study, as many as 40 percent of people reporting a fish allergy had no problems with fish until they were adults.

    Having an allergy to a finned fish (such as tuna, halibut or salmon) does not mean that you are also allergic to shellfish (shrimp, crab and lobster). While some allergists recommend that individuals with a fish allergy avoid eating all fish, it may be possible for someone allergic to one type of fish to safely eat other kinds. If you are allergic to a specific type of fish, your allergist can help you determine whether other varieties may be safe to eat, so you can take control of your fish allergy and start enjoying life again.

    Fish Allergy Symptoms

    • Hives or a skin rash
    • Nausea, stomach cramps, indigestion, vomiting and/or diarrhea
    • Stuffy or runny nose and/or sneezing
    • Headaches
    • Asthma
    • Anaphylaxis (less common), a potentially life-threatening reaction that impairs breathing and can cause the body to go into shock

    For more information on fish allergy symptoms click here.

    Fish Allergy Management and Treatment

    • Avoid fish and fish products.
    • Read food labels carefully.
    • Treat symptoms of anaphylaxis with epinephrine (adrenaline).

    For more information on fish allergy management and treatment click here.

    As with other food allergies, the symptoms of a fish allergy may range from mild to severe. They include:

      or a skin rash
  • Nausea, stomach cramps, indigestion, vomiting and/or diarrhea
  • Stuffy or runny nose and/or sneezing
  • Headaches
  • Asthma (less common), a potentially life-threatening reaction that impairs breathing and can cause the body to go into shock
  • Your allergist may diagnose an allergy to a specific kind of fish through a skin-prick test or a blood test.

    In the skin-prick test, a small amount of a liquid containing protein from the fish being tested is placed on the back or forearm, which is then pricked with a small, sterile probe to allow the liquid to seep into the skin. If a raised, reddish spot forms within 15 to 20 minutes, that can indicate an allergy.

    In the blood test, a blood sample is sent to a laboratory to test for the presence of immunoglobulin E antibodies to protein from the fish being tested.

    If these tests aren’t definitive, your allergist may order an oral food challenge. Under medical supervision, you’ll eat small amounts of fish or a fish product to see if a reaction develops. Because of the possibility that a reaction could be severe, this test is conducted in your allergist’s office or at a food challenge center with emergency equipment and medication on hand.

    Managing a fish allergy includes strict avoidance of the fish to which you are allergic. Doctors typically advise people who are allergic to one type of finned fish to avoid all types. If you are allergic to a specific fish and would really like to have other varieties of fish in your diet, speak to your allergist about testing for those varieties. Do not change your diet without guidance from your allergist.

    Fish is one of eight allergens with specific labeling requirements under the Food Allergen Labeling and Consumer Protection Act of 2004. Under that law, manufacturers of packaged food products sold in the U.S. and containing fish or a fish product as an ingredient must identify on the ingredient label, in clear language, the specific type of fish used.

    Many prepared foods contain fish in some form. Fish is a common ingredient in Worcestershire sauce and Caesar salad and is sometimes found in imitation crab products in the form of surimi, a processed food made mainly from Alaska pollock. Fish is also prevalent in Asian cuisine, which uses fish-based stock for many dishes.

    While an allergy to fish protein is most common, it is possible to be allergic to fish gelatin (made from fish skin and bones). People with a fish allergy should consult their allergist before taking fish oil dietary supplements.

    If your allergist gives you the go-ahead to eat certain types of fish, take extra precautions to avoid eating fish that has come in contact with the type of fish that causes your allergic reaction. Be advised that some restaurants may substitute cheaper types of fish for what is on the menu (for example, what is listed as red snapper could really be tilapia). Since many types of fish look alike once they are filleted, dishonest suppliers to supermarkets may substitute cheap fish for more expensive types, according to an investigation by Oceana, a conservation nonprofit.

    To avoid either cross-contact or the possibility of eating a mislabeled fish, be sure to tell whoever handles the fish you plan to eat about your allergy. Ask whether there is a risk that you will eat something that triggers your allergy.

    Due to the high risk for cross-contact during food preparation, it is best to avoid seafood restaurants in general, even if you plan to order something other than fish. Stay out of areas where fish is being cooked, as proteins may be released into the air during cooking.

    People with a fish allergy do not necessarily have to avoid shellfish (and vice versa) there appears to be no relationship between fish and shellfish allergies. However, an individual can be allergic to both fish and shellfish, just as someone can be allergic to both eggs and peanuts.

    Treatment for fish allergy includes strict avoidance of the fish to which you are allergic. Because fish is often implicated in cases of food-induced anaphylaxis, allergists advise fish-allergic patients to treat symptoms of a reaction with epinephrine (adrenaline), which is prescribed by your doctor and administered in an auto-injector. Anaphylaxis can come on quickly and can be fatal unless epinephrine is injected as soon as you notice symptoms developing. Be sure to call for an ambulance, and alert the dispatcher that epinephrine has been used and more may be needed.

    Only epinephrine can reverse the symptoms of anaphylaxis for less severe symptoms, you may find that antihistamines are helpful.

    Life’s too short to struggle with allergies to fish. Find answers with an allergist.

    How Food Allergies Are Linked to Joint Pain

    Can food allergies affect joint pain? Here&rsquos an explanation of the link between joint pain and food allergies:

    1. Inherited

    Not only are seasonal allergies common in many individuals, but so are food allergies. However, sometimes people inherit allergies to specific types of food, and it&rsquos hard to predict the condition among families. A family member could develop allergies to a specific type of food at any point in their lives.

    2. Immune System

    As mentioned, soy, fish, tree nuts, peanuts, shellfish, eggs and wheat are common allergy-causing foods in many individuals. The immune system overreacts to a particular type of food or its components. In these cases, it responds to the food&rsquos proteins as harmful substances entering the body, like how toxins invade, leading to the overreaction that causes several symptoms. These symptoms include:

    • Coughing
    • Vomiting
    • Wheezing
    • Breathing problems
    • Shock
    • Weakened pulse
    • Hives and hoarse throat
    • Difficulty swallowing food
    • Feeling faint

    These symptoms typically impact the gastrointestinal, cardiovascular and respiratory systems. Food allergies could even lead to anaphylaxis &mdash a life-threatening condition where you&rsquore unable to properly breathe, resulting in shock. In these cases, joint pain occurs.

    3. Inflammation

    Allergens can trigger the immune system to produce inflammation, leading to joint pain in different areas of the body. This explains why patients with arthritis feel severe joint pain after they eat particular foods they&rsquore allergic to.

    Eye Allergy

    Nothing is more irritating than the feeling that there is something in your eye. But if your eyes are red and irritated, and you don’t see anything in them, it could be allergies. Symptoms can occur independently but usually accompany the sneezing, sniffling or stuffy nose related to nasal allergies. An allergist can determine whether an eye allergy is the source of your symptoms.

    Eye Allergy Symptoms

    For more information on eye allergy symptoms click here.

    Eye Allergy Triggers

    • Outdoor allergens, such as pollens from grass, trees and weeds
    • Indoor allergens, such as pet dander, dust mites and mold
    • Irritants, such as cigarette smoke, perfume and diesel exhaust

    Eye Allergy Management and Treatment

    Avoid triggers by making changes to your home and your routine.

    • Keep windows closed during high pollen periods use air conditioning in your home and car.
    • Wear glasses or sunglasses when outdoors to keep pollen out of your eyes.
    • Use “mite-proof” bedding covers to limit exposure to dust mites, and a dehumidifier to control mold.
    • Wash your hands after petting any animal.

    Control some symptoms with nonprescription medications, sold over the counter:

    • Artificial tears
    • Decongestant eyedrops (don’t use eyedrops for “red eye” longer than a week, or they can make things worse)
    • Oral antihistamines (note that they may dry your eyes and make your symptoms worse)

    See an allergist for prescription medications, which may be more effective:

    • Eyedrops (decongestant, antihistamine, mast cell stabilizer, corticosteroid, NSAID)
    • Allergy shots (immunotherapy)
    • Nonsedating oral antihistamines (note that they may dry your eyes and make your symptoms worse)

    For more information on eye allergy management and treatment click here.

    Eye allergies develop when the body’s immune system becomes sensitized and overreacts to something in the environment that typically causes no problem in most people. An allergic reaction can occur when that “something” (called an allergen) comes in contact with antibodies attached to the mast cells in your eyes the cells respond by releasing histamine and other substances or chemicals that cause tiny blood vessels to leak and the eyes to become itchy, red and watery.

    Eye allergies share symptoms with some diseases of the eye, making accurate diagnosis imperative. The symptoms of eye allergy can range from mildly annoying redness to inflammation severe enough to impair vision. If symptoms persist or over-the-counter remedies do not bring relief, see an allergist, who will review your medical history and symptoms and conduct tests that can reveal an eye allergy.

    Those tests may include an examination with a microscope, which will show swollen blood vessels on the surface of the eye. In addition, your doctor may test for a certain type of white blood cell that shows up on areas of the eye affected by allergies. This involves gently scraping the conjunctiva (the inner lining of the eyelid) and seeing if those cells are found.

    It’s clear that the over the counter treatments have helped. It’s very clear that they can help. However, for long-term care, you really need to prevent. You need prescription and an intervention with education to maximize the outcome and to hopefully prevent the development of ocular allergies to the point where it interferes with your daily lives.

    Allergist Leonard Bielory, MD

    The primary types of eye allergy are seasonal or perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis, contact allergic conjunctivitis and giant papillary conjunctivitis.

    Seasonal and perennial allergic conjunctivitis

    Seasonal allergic conjunctivitis (SAC) is by far the most common type of eye allergy. Patients experience symptoms in spring, summer or fall, depending on the type of plant pollens in the air. Typical symptoms include:

    People with SAC may have chronic dark circles (known as allergic shiners) under their eyes. The eyelids may be puffy, and bright lights may be bothersome. SAC symptoms often accompany the runny nose, sneezing and nasal congestion associated with hay fever and other seasonal allergies. The itching may be so bothersome that patients rub their eyes frequently, making symptoms worse and potentially causing infection.

    Perennial allergic conjunctivitis (PAC), as its name implies, occurs year-round. Symptoms are the same as with SAC, but tend to be milder. They are caused by reactions to dust mites, mold, pet dander or other household allergens, rather than pollen.

    Vernal keratoconjunctivitis

    Vernal keratoconjunctivitis is a more serious eye allergy than SAC or PAC. While it can occur year-round, symptoms may worsen seasonally. It primarily occurs in boys and young men about 75 percent of patients also have eczema or asthma. Symptoms include:

    • Itching
    • Significant tearing and production of thick mucus
    • The feeling of having something in the eye (foreign body sensation)
    • Aversion to light (photophobia)

    If left untreated, vernal keratoconjunctivitis can impair vision.

    Atopic keratoconjunctivitis

    This type of allergy primarily affects older patients - mostly men with a history of allergic dermatitis. Symptoms of atopic keratoconjunctivitis can occur year-round and are similar to those of vernal keratoconjunctivitis:

    • Severe itching
    • Burning
    • Redness
    • Significant production of thick mucus that, after sleep, may cause the eyelids to stick together

    If left untreated, atopic keratoconjunctivitis can result in scarring of the cornea and its delicate membrane.

    Contact allergic conjunctivitis

    This can result from irritation by contact lenses or by the proteins from tears that bind to the surface of the lens. Symptoms include:

    Giant papillary conjunctivitis

    Associated with wearing contact lenses, giant papillary conjunctivitis is a severe form of contact allergic conjunctivitis in which individual fluid sacs, or papules, form in the upper lining of the inner eyelid. Symptoms include:

    • Itching
    • Puffiness
    • Tearing
    • Mucous discharge
    • Blurred vision
    • Poor tolerance for wearing contact lenses
    • Foreign body sensation

    The first approach in managing seasonal or perennial forms of eye allergy should be to avoid the allergens that trigger your symptoms.

    • Stay indoors as much as possible when pollen counts are at their peak, usually during the midmorning and early evening, and when wind is blowing pollens around.
    • Avoid using window fans that can draw pollens and molds into the house.
    • Wear glasses or sunglasses when outdoors to minimize the amount of pollen getting into your eyes.
    • Try not to rub your eyes, which will irritate them and could make your condition worse.
    • Keep windows closed, and use air conditioning in your car and home. Air conditioning units should be kept clean.
    • Reduce exposure to dust mites, especially in the bedroom. Use “mite-proof” covers for pillows, comforters and duvets, and mattresses and box springs. Wash your bedding frequently, using hot water (at least 130 degrees Fahrenheit).
    • To limit exposure to mold, keep the humidity in your home low (between 30 and 50 percent) and clean your bathrooms, kitchen and basement regularly. Use a dehumidifier, especially in the basement and in other damp, humid places, and empty and clean it often. If mold is visible, clean it with detergent and a 5 percent bleach solution.
    • Clean floors with a damp rag or mop, rather than dry-dusting or sweeping.
    • Wash your hands immediately after petting any animals. Wash your clothes after visiting friends with pets.
    • If you are allergic to a household pet, keep it out of your home as much as possible. If the pet must be inside, keep it out of the bedroom so you are not exposed to animal allergens while you sleep.
    • Close the air ducts to your bedroom if you have forced-air or central heating or cooling. Replace carpeting with hardwood, tile or linoleum, all of which are easier to keep dander-free.

    Many allergens that trigger eye allergies are airborne, so you can’t always avoid them. Discuss your symptoms with your allergist to determine which treatment options are right for you.

    Nonprescription (over-the-counter, or OTC) eyedrops and oral medications are commonly used for short-term relief of some symptoms. They may not relieve all symptoms, and prolonged use of some OTC eyedrops may actually cause your condition to worsen.

    Prescription eyedrops and oral medications also are used to treat eye allergies. The prescription drops provide both short- and long-term targeted relief of eye allergy symptoms. See an allergist for expert care and relief.

    Children can be treated with both OTC and prescription eyedrops and medications. Artificial tears are safe and can be used at any age. Some eyedrops, such as antihistamines and mast cell stabilizers, can be used in children 3 and older. Any treatment should be discussed with your child’s physician.

    OTC eyedrops and medications

    • Tear substitutes: Artificial tears can temporarily wash allergens from the eye and also moisten the eyes, which often become dry when red and irritated. These drops, which can be refrigerated to provide additional soothing and comfort, are safe and can be used as often as needed.
    • Decongestants: OTC decongestant eyedrops reduce the redness associated with eye allergies by narrowing the blood vessels in the eye. (Note: These should not be used by anyone with glaucoma.) They are available with a decongestant only or with a decongestant and an OTC antihistamine, which provides additional relief from itching. Because the drops are weak, they must be used frequently (four to six times a day).


    If you have an allergy that occurs over several seasons, you may be allergic to the spores of molds or other fungi. Molds live everywhere. Upsetting a mold source can send the spores into the air.

    Mold and mildew are fungi. They are different from plants or animals in how they reproduce and grow. The “seeds,” called spores, travel through the air. Some spores spread in dry, windy weather. Others spread with the fog or dew when humidity is high.

    Inhaling the spores causes allergic reactions in some people. Allergic symptoms from fungus spores are most common from July to early fall. But fungi grow in many places, both indoors and outside, so allergic reactions can occur year round.

    Although there are many types of molds, only a few dozen cause allergic reactions. Many molds grow on rotting logs and fallen leaves, in compost piles and on grasses and grains. Unlike pollens, molds do not die with the first killing frost. Most outdoor molds become inactive during the winter. In the spring they grow on plants killed by the cold. Indoors, fungi grow in damp areas. They can often be found in the bathroom, kitchen or basement.

    What Are the Symptoms of a Mold Allergy?

    The symptoms of mold allergy are very similar to the symptoms of other allergies, such as sneezing, itching, runny nose, congestion and dry, scaling skin.

    • Outdoor molds may cause allergy symptoms in summer and fall (or year-round in some climates)
    • Indoor molds may cause allergy symptoms year-round

    Mold spores get into your nose and cause hay fever symptoms. They also can reach the lungs and trigger asthma. A chemical released by allergy cells in the nose and or lungs causes the symptoms. Sometimes the reaction happens right away. Sometimes a mold allergy can cause delayed symptoms, leading to nasal congestion or worsening asthma over time. Symptoms often get worse in a damp or moldy room like a basement. This may mean you have a mold allergy.

    Rarely, some patients can have a more serious illness called allergic bronchopulmonary aspergillosis. In this condition, there is both an allergic and an inflammatory response to the mold. Symptoms may include severe wheezing, coughing and shortness of breath, much like asthma.

    Food fungi, like mushrooms, dried fruit, or foods containing yeast, vinegar or soy sauce, usually don’t cause allergy symptoms of the nose, eyes and lungs. It is more likely that reactions to food fungi are caused by the food's direct effect on blood vessels. For example, fermented foods (like wine) may naturally contain a substance known as histamine. Histamine is also a chemical your allergy cells release during an allergic reaction. Foods that contain histamines can trigger allergy-like responses when you consume them.

    How Do Doctors Diagnose Mold Allergy?

    To diagnose an allergy to mold or fungi, the doctor will take a complete medical history. If they suspect a mold allergy, the doctor often will do skin tests or allergen specific IgE blood tests. Extracts of different types of fungi may be used to scratch or prick the skin. If there is no reaction, then you probably don’t have an allergy. The doctor uses the patient's medical history, the skin testing results and the physical exam to diagnose a mold allergy.

    How Can I Prevent an Allergic Reaction to Mold?

    There is no cure for allergies. But you can reduce your allergy symptoms by avoiding contact with the mold spores. Several measures will help:

    Reduce Your Exposure to Mold Spores Outside

    • Limit your outdoor activities when mold counts are high. This will lessen the amount of mold spores you inhale and your symptoms.
    • Wear a dust mask when cutting grass, digging around plants, picking up leaves and disturbing other plant materials.

    Reduce Your Exposure to Mold Spores Inside

    • Use central air conditioning with a CERTIFIED asthma & allergy friendly® filter attachment. This can help trap mold spores from your entire home. Freestanding air cleaners only filter air in a limited area. Avoid devices that treat air with heat, electrostatic ions or ozone.
    • Lower your indoor humidity. No air cleaners will help if excess moisture remains. If indoor humidity is above 50%, fungi will thrive. A hygrometer is a tool used to measure humidity. The goal is to keep humidity below 45%, but below 35% is better.

    To Reduce Mold in Your Bathrooms:

    • Use an exhaust fan or open a window in the bathroom during baths and showers.
    • Remove bathroom carpeting from places where it can get wet.
    • Scour sinks and tubs at least monthly. Fungi thrive on soap and other films that coat tiles and grout.
    • Quickly repair any plumbing leaks.

    To Reduce Mold in Your Kitchen:

    • Clean garbage pails frequently.
    • Clean refrigerator door gaskets and drip pans.
    • Quickly repair any plumbing leaks.
    • Use an exhaust fan when you are cooking or washing dishes.

    To Reduce Mold in Your Laundry Area:

    • Remove clothes from washing machine promptly.
    • If you have a front-loading washing machine, clean the rubber seal and inside of the door. Leave the door cracked open when the machine is not in use.
    • Don’t leave wet, damp clothes sitting around.
    • Make sure your laundry area has good air circulation.

    To Reduce Mold in Your Bedrooms:

    • Polyurethane and rubber foams seem especially prone to fungus invasion. Use plastic covers on bedding made from these foams.
    • Throw away or recycle old books, newspapers, clothing or bedding.
    • Check windows for condensation (water droplets or mist).
    • Improve air flow through your bedroom. If your closet is colder than the rest of your room, leave the closet doors open.

    To Reduce Mold in Your Basement:

    • Quickly repair any plumbing leaks.
    • Promote ground water drainage away from a house. Remove leaves and dead vegetation near the foundation and in the rain gutters.

    To Reduce Mold in Your Whole House:

    • Use an electric dehumidifier to remove moisture and keep humidity in your house below 45 percent. Drain the dehumidifier regularly and clean the condensation coils and collection bucket.
    • Increase air flow in your home. Open doors between rooms, move furniture away from walls and use fans if needed.
    • Repair roof leaks and roof gutters. Clean out your gutters to remove leaves and debris. When gutters are full or damaged, it can cause leaking.

    What Are the Treatments for Mold Allergy?

    In some cases, there may be ways to reduce or remove mold exposure. This may not always be possible and you may need medications.

    • Avoid contact with mold. (See tips above)
    • Take medications for nasal or other allergic symptoms. Antihistamines and nasal steroids are available over the counter without a prescription. If you have allergic asthma, talk to your doctor about which medicines may be best for you. You might also be a candidate for allergy shots. Allergy shots may help reduce symptoms and medications. Learn more about allergy treatments.

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