One day, as soon as you are about to devour your favorite fruit the water starts rushing out of your eyes, your nose starts running, not because you are happy for such a delightful moment instead it is your intricate immune system yelling “Oh! Our dear beholder, that fruit is your enemy, you must sacrifice your desires to survive.”
This protective response shown by your immune system as soon as it comes in contact with a foreign undesirable substance; ‘allergen’ is known as allergy. These allergens may include pollen, grasses, dust, bacteria and some medications etc.
Your body tends to know these allergens as antigens. American Academy of allergy asthma and immunology calls allergic reaction an overreaction of body to otherwise harmless agent.
How Allergy Develops
The invasion of any antigen in the body is identified by the help of antibodies which are produced by the immune system as a result of foreign substance invasion. Precisely, antibodies are your defense brigade, which target or remove foreign substances, viruses and bacteria etc., from the body.
There are five different classes of antibodies, IgG, IgM, IgA, IgE and IgD which are specific for different types of antigens. The IgE antibodies are the common players in all types of allergic reactions. These bind to the allergen and then to a receptor on mast cells or basophils and trigger the release of inflammatory chemicals such as histamine. High plasma histamine levels illustrate the symptoms of allergic responses.
Human body is designed in certain pattern which allows any foreign substance after entering into the body to be detected by immune system and which reacts by fighting against infections, viruses and bacteria. Some people have over -sensitive immune systems therefore allergic reactions in response to certain harmless agents are displayed.
Entry of an antigen in the body is followed by triggering IgE antibodies. These antibodies travel to the cells and release chemicals that prompt symptoms most often associated with nose, lungs, throat, sinuses, ears, lining of the stomach or on the skin etc.
When a person gets exposed to an allergy causing substance for the first time, allergic responses are not necessarily shown.
However, after getting sensitized to a specific allergen, even minor exposure in future can produce a severe allergic reaction. The most frequently affected organs of the body by allergy are skin and mucous membranes.
Types Of Allergies
European Centre for Allergy Research foundation formulated a criterion to characterize different types of allergies. According to them, allergies can be divided into four main categories based on the reaction mechanism and reaction time.
TYPES Type I – Immediate reaction (Anaphylactic reaction)
Type II – Cytotoxic
Type III – Immune complex allergies
Type IV – Delayed-onset allergies (Cellular immune reaction)
Type I: Immediate Reaction (Anaphylactic reaction)
These types of allergies develop within seconds or minutes and affect skin or mucous membranes. Almost all of the common anaphylactic allergies are caused by proteins. Some of the examples are: Hay fever (allergic rhinitis), Animal hair allergy, Insect venom allergy, Latex allergy, Dust mite allergy, Food allergy, Medication allergy (local anaesthetics, antibiotics), Allergic asthma, Urticaria (hives), Angioedema and Anaphylactic shock.
Type 2 Allergies: Cytotoxic
When body’s cells are damaged and considered as allergens by immune system, this type of response is considered as cytotoxic and is not commonly exhibited by the body. For instance: Blood transfusion reactions, autoimmune-haemolytic anemia, Myasthenia Gravis, Agranulocytosis and Blood group intolerance allergy.
Type 3: Immune Complex Allergies
The allergies due to medication, which affect skin or kidneys and lead to inflammation causing skin rash, often in conjunction with hemorrhage, skin damage and itching are termed as immune complex allergies. Examples include Vasculitis (inflammation of the blood vessels), Serum illness, Alveolitis, Farmer’s Lung, Nephritis (inflammation of the kidneys) and Arthritis (inflammation of the joints) etc.
Type 4: Delayed-Onset Allergies
These allergic reactions occur after 12 to 72 hours of contact with the allergen. Some of the examples are: Transplant rejection, Contact allergies (e.g. nickel allergy), Tuberculin reaction (TBC test), Rashes due to medication allergy.
Perils Of Allergy
The term was coined in 1901 by Charles Richet and Paul Portier while experimenting with glycerin-extracts of the sea anemone. Prophylaxis gave opposite results on the project they were working on so they called it anaphylaxis, ‘ana’ in Greek means ‘opposite’ and ‘phlaxis’ for ‘protection’.
A serious and life-threatening allergic reaction involving multiple parts of the body is known as anaphylaxis. Generally, this response is exhibited against anything that a person is allergic to, it can be due to food, insect’s sting, specific medication or any materials like latex.
Common allergy causing symptoms occur mostly in one specific location of the body but anaphylactic allergic reactions affect more than one part of the body simultaneously.
– Symptoms of Anaphylaxis:
Since it affects a collection of systems, signs, and symptoms spread across the whole body, e.g., itching, swelling of lips or tongue, followed by tightness or constriction of throat. Hives on the skin along with redness and swelling is also observed. Vomiting, diarrhea and cramps are ensued if the gut is affected in case of anaphylaxis.
The presence of all allergy symptoms are not necessary for the characterization of an allergic reaction as anaphylaxis, only few of the above mentioned symptoms can be present at a time.
– Anaphylactic Shock:
It occurs within seconds or minutes of exposure to an allergen. Due to a cascade of chemicals released to fight against allergy causing agent, the body can undergo shock known as anaphylactic shock.
Serious medical attention followed by an injection of epinephrine is advised by the doctor in case of anaphylactic emergency, which otherwise can turn into a fatal condition. The respiratory system showcases anaphylaxis by shortness of breath, coughing, and wheezing. Severe infection critically affects the heart resulting in weak pulse, dizziness and even passing out.
People with asthma or family history of anaphylaxis are more prone to developing anaphylactic allergies. Previous exposure of the infection increases the risks of developing another episode.
The allergic reactions demand proper diagnosis and management on acute stages while medical care from a registered allergist or immunologist can minimize future exposures.
– Venom Anaphylaxis
Stings from bees and wasps can cause severe allergic reactions, including anaphylaxis. People with oversensitive immune systems trigger allergies due to insect stings including bee, wasp, hornet, fire ant etc. Such allergic reactions can turn into immediate anaphylactic shock which can be fatal. However, most people are not allergic to insect stings and may mistake a normal sting reaction for an allergic reaction.
Hay Fever (Allergic Rhinitis)
An immune disorder characterized by an allergic response to pollen grains and other substances is known as Hay fever. The medical terminology for Hay fever is allergic rhinitis. It is a type of respiratory allergy that can either be seasonal i.e. occurring mostly in spring due to plants pollens, or can be perennial, which occurs all year round. Pollen Allergies due to pollen grains from flowers and trees can enter the respiratory tract, leading to sniffling and sneezing.
As spring season comes, people suffering from hay fever go missing. It is considered as a proper illness therefore the specialists advice patients to take this allergic condition seriously. The most common symptoms associated with hay fever are sneezing, itching, tearing, redness of the eyes, swelling of the nasalpassages and runny nose.
Decades ago hay fever was caused only due to contact with grass and hay but these days coming in contact with different trees, grass, weed pollens, animal hair, dust mites, or mold can also result in rhinitis i.e. Hay fever or conjunctivitis-pink eye.
- Allergic Conjunctivitis (Pink Eye)
Another complication associated with hay fever is allergic conjunctivitis. Though conjunctivitis caused by bacteria, viruses, or STDs can spread easily from person to person but allergic conjunctivitis is not contagious. Generally, it is not a serious medical complication and can be reduced by using eye drops which help to dilute and remove allergens.
However, prolong allergic condition needs medications like topical antihistamines, mast cell stabilizers, non-steroidal anti-inflammatory drugs (NSAIDs), and corticosteroids. Surgical intervention may be indicated in severe cases.
Since hay fever affects the respiratory system, various infections like Bronchitis can also occur, resulting in coughing and allergic asthma. According to European Centre for Allergy Research Foundation, 80% of respiratory allergies are triggered by the airborne allergens.
Inflammation develops along the nasal passages along making the bronchioles irritating and with increased mucous discharge. Acute bronchitis includes sputum production, sore throat, nasal congestion, headache, muscle aches and mild fever.
Medications like cough suppressant are commonly advised by the doctors. Other options like oxygen therapy or pulmonary rehabilitation can provide better management of the allergy. Antibodies are used in case of viral or bacterial bronchitis. Acute allergy can last for 10 days.
However, coughing might last for several weeks after fighting the infection. Chronic bronchitis which results mainly from smoke might last for two years. The lung passages are constantly irritated in such condition.
Home remedies like drinking plenty of fluids, taking fever reducing medicines, washing hands, eating healthy balanced diet, exercising regularly and trying to stay away from lung irritants can reduce the risks of bronchitis infections.
- Atopic Dermatitis
According to American Academy of Dermatology, atopic dermatitis is a skin allergic condition also known as eczema. Dry and scaly patches appear on the skin including face, forehead, and scalp. Children are mostly affected by this condition. Other symptoms like itching and, red bumpy rashes on the creases of the elbows and knees are also very common.
It is not a contagious disease rather it is caused by hereditary and environmental factors. It is mostly present in combination with hay fever and asthma.
Dermatologically approved moisturizers for dry skin are generally recommended for reducing the dryness and itchiness of the skin. Petroleum jelly, wet wrap therapy and avoiding contact with hot water has been positively associated with reducing the symptoms of the allergy.
- Latex Allergy
Latex is the white milky substance produced by the trees, which is used in manufacturing of gloves, balloons, rubber bands, erasers, and toys etc. The proteins present in the natural rubber latex can cause clinical symptoms such as angioedema (deep swelling of skin), cough, asthma, and anaphylactic reactions. Alternate natural latex from the desert plant guayule is now being used for many products, which has provided allergic relief for many patients with latex allergy.
- Food Allergies
The unusual immune response to different types of foods is known as food allergy. Most of the time allergic responses are translated due to the proteins in food. These types of allergies are diagnosed in early years mostly; however, in adolescence or old age some of these can develop with time or due to exposure to certain kinds of food.
Typical allergens include; cow’s milk, eggs, fish, peanuts, shellfish, soy, tree nuts and wheat. 90% of food intolerances are caused by these foods.
An allergic reaction, for instance anaphylaxis, respiratory distress or dermatitis, when untreated for prolonged time can lead to death. The prevailing reactions can also result in a fatal anaphylactic shock in the body, which might cause heart or multiple organ failure if epinephrine is not administered immediately along with long-term emergency monitoring. This transpires because the chemicals released in the body by the antibodies, in response to allergens e.g. bee venom, attack the tissues of the body leading to organ failure.
Differentiating between food allergies and food intolerance can be a taxing job, since both conditions can have similar symptoms, but it is necessary that we draw a fine line between them. The symptoms of food allergies are more severe and long lasting due to the involvement of the immune system, meanwhile food intolerance is limited to the digestive system.
What Is Food Allergy?
When immune system mistakes a substance present in food as something dangerous and grows immunity against it, such condition affects whole body, not just the stomach. Symptoms like rash, hives, itchy skin and shortness of breath prevails, denoting a type of immune-allergic response known as a food allergy.
Most food allergies are marked by sudden drop in blood pressure, trouble in swallowing or breathing which might lead to choking. Food allergies can escalate quickly into a fatal condition. Immediate medical attention should be taken to minimize the damaging effects.
Gluten Allergy Or Celiac Disease
Gluten is a protein found in wheat, rye and barley. People with celiac disease are more likely to suffer adverse health effects as it is an auto-immune disorder and can cause serious damage to small intestine upon gluten ingestion especially microvilli i.e. small structures present in the intestines associated with the task of nutrient absorption.
Celiac disease is a hereditary acquired disorder and people with family history of gluten intolerance are more prone to developing the allergy. If proper treatment is not performed at an early stage it can transform into potentially harmful conditions including type I diabetes, multiple sclerosis (MS), dermatitis herpetiformis (an itchy skin rash), anemia, osteoporosis, infertility and miscarriage.
Neurological conditions like epilepsy and migraines, short stature, and intestinal cancers, eczema, allergic rhinitis, bronchospasm (asthma-like symptoms) and even anaphylaxis can occur due to gluten ingestion in intolerant patients.
Screening via endoscopy is executed in most of the people to diagnose celiac disease. Gluten free diet is recommended to avoid the harmful risks of allergy.
What Is Food Intolerance?
Food intolerance can be characterized as a situation when irritation due to undigested food takes place in the GI tract. Bloating, gas, vomiting, cramps, heartburn, headaches, irritability or nervousness are the key symptoms. Immune system has no role to play with the food intolerance, while food allergies can turn out to be life threatening sometimes due to the over sensitivity of immune function.
Lactose is a sugar found in milk and dairy products. According to NHS, UK, lactose intolerance is the most widespread food related problem characterized by indigestibility of lactose. Symptoms start to appear as soon as milk in any form is consumed, even tea or coffee.
Normally, lactose is broken down into two sugars known as glucose and galactose by a substance called lactase, which ensures easy absorption of the sugar in the blood.
Lactose intolerants cannot produce enough lactase, thus leaving lactose in undigested forms in the stomach and production of various gases causing bloating, stomach cramps and pains or even diarrhea in some cases. Lactose intolerance is generally an inherited and a long term condition.
However, in some cases it can be temporary and might be developed for some days or weeks only.
How To Combat Food Allergies?
In U.S. food labeling of the common allergens is a must. It is recommended to ask about the food ingredients used in the recipes whenever dining out. Even small amounts of food can stimulate serious allergies.
People in Western countries carry auto-injectable epinephrine and anti-histamine injections to combat foodborne allergic conditions. Complete medical history and the food recall are performed as diagnostic tools. The allergist track downs all the foods eaten along with frequency and any symptoms of allergy produced during the allergic time period.
1- Physical Examination (skin Tests):
In order to determine the common allergy caused by a specific food, a small amount of food extract is smeared on the back of the arm. If hives are formed within 20 minutes then food allergy to that specific food is confirmed. In addition to this, other tests like skin prick test, skin scratch test, and intradermic skin test along with skin scrape test are generally used for diagnostic purposes.
2- Serum IgE Test:
If a person has severe eczema skin tests are not recommended therefore, for the diagnosis of food allergy an IgE blood serum laboratory test is advised by the doctor, high levels in blood of these antibodies have been positively correlated.
Resistance Against Allergies:
Children usually outgrow food allergies to cow’s milk, egg, soy and wheat with age. Proper medical care and repeated allergy testing can help to lessen the extent of allergic conditions.
A new study carried out in California suggests that eating peanut snacks in the first years of life reduces the risk of a nut allergy in children. The risks of having peanut allergy are amplified if another allergic condition like eczema or asthma is persistent. Avoiding nuts especially tree nuts like cashews, walnuts, can help to prevent a reaction.
What Can Cause An Allergic Reaction?
Allergic reactions are sensitivities to substances called allergens that come into contact with the skin, nose, eyes, respiratory tract, and gastrointestinal tract. Allergic reactions are common. The immune response that causes an allergic reaction is similar to the response that causes hay fever.
Many allergic reactions are mild, while others can be severe and life threatening. They can be confined to a small area of the body, or they may affect the entire body.
Oral Allergy Syndrome
Some people can manifest allergic reaction after ingesting certain types of fruits and vegetables, this response is known as oral allergy syndrome. According to a research, symptoms outside the gastrointestinal tract were observed in 8.7% of patients and anaphylactic shock in 1.7%.
Fresh food skin prick test is usually performed for the confirmation of this type of allergy.
Food Protein-Induced Enterocolitis Syndrome (FPIES)
Allergic response characterized by vomiting, diarrhea, and dehydration leading to severe lethargy, change in body temperature and blood pressure is known as FPIES. It is a non-IgE bound allergy, unlike common food allergies; symptoms are not manifested immediately and are not shown by standard allergy tests.
It is mostly triggered by proteins in cow milk and sometimes by soy. In infants, breast milk (sometimes) and solid foods like rice and oats can be the cause. Atopy Patch Testing (APT) is used by the doctors for correct diagnosis.
Chronic Fatigue Immune Dysfunction (CFIDS) And Allergic Reactions:
The Chronic Fatigue Immune Dysfunction (CFIDS) is a condition in which the immune system compels the body to undergo severe fatigue in response to an exogenous stimulus i.e. allergic reaction. Allergens which can provoke an immune response include viruses and bacteria.
The condition is hard to diagnose because the symptoms resemble normal fatigue very closely. The all-encompassing fatigue caused by CFIDS incapacitates an individual and does not improve with rest.
Physical activity and increasing mental anxiety further worsens the condition and greatly reduces the stamina of the affected individual. It is considered as an autoimmune disease; however CFIDS remain controversial due to a lack of scientifically proved researches that verify its correlation with immunity. Some of the symptoms include:
- Amplified malaise i.e. extreme exhaustion & sickness
- Mental exertion
- Difficulties with sleep
- Troubles with cognitive abilities i.e. memory & concentration
- Persistent muscle pain
- Pain in joints
- Tendering of lymph nodes in the neck or armpit area
- Sore throat
- Gastro-intestinal problems
Other Types Of Allergies
Some people experience other types of allergies including; Shellfish Allergy, Sulfite Allergy (due to food preservative and taste enhancer), Soy allergy due to beans, Casein allergy (protein in milk).
Mold allergy due to fungus and dust allergies are also observed in many people along with pet allergies including sensitivity to dogs, cats etc. Antibiotic allergy including penicillin is also prevalent in some individuals. Chemical allergy due to different chemicals in shampoos, cosmetics, and detergents can also trigger allergic skin reactions.
Seasonal allergies — also called hay fever and allergic rhinitis — can make you miserable. But before you settle for plastic flowers and artificial turf, try these simple strategies to keep seasonal allergies under control.
Pollen And Mold Allergies
Many people with sensitive immune system become the victims of seasonal allergies due to substances like grass, pollen and mold present in the environment. Sneezing, coughing, irritation of eyes accompanied by a runny nose mostly in spring and fall confirms the presence of seasonal allergies.
Ragweed is a plant which blooms to its fullest and releases pollen during August to November time of the year. The pollen grains from the plants and grasses being light weight travel with air and result in hay fever.
Spring allergies usually start in February and last until May. Rain in the spring season ends up increasing spore production of fungal mold, which upon inhalation by humans, can cause respiratory allergies. The severity of the symptoms depends upon prevailing climatic conditions.
Management Of Seasonal Allergies
Seasonal allergies can be managed by diagnosing the triggers for your specific allergy. An allergist can help you by suggesting accurate information about the pollen and mold counts during allergy seasons, which is usually provided by weather reports. Allergy specialists recommend keeping windows and doors closed at home and while traveling to avoid contracting seasonal allergies. Similarly, proper cleansing and showers are also advised upon coming home to evade allergens.
Treatment For Seasonal Allergies
Medications such as nose and eye drops for are usually prescribed for seasonal allergies to provide a soothing and relieving effect.
Allergy Shots (Immunotherapy)
Injections containing small amounts of extracted allergen are introduced into the skin via arm to build toleration. These may be given once or twice a week for a period of 7 months which can later be reduced to 4 weeks depending upon the severity of symptoms. However, for some people the therapy can last for over 4 to 5 years.
More than 50 million Americans have an allergy of some kind. An estimated 4-6% of children and 4% of adults suffer from food allergies as stated by the Centers for Disease Control and Prevention (CDC).
Life is not easy for people with oversensitive immune systems. Specific changes to the immune system in some immuno-deficiency diseases increase the risk of the developing allergies to a great extent.
However, there are ways to avoid some forms of allergies. For example, seasonal allergies like hay fever can be prevented by limiting unnecessary out-door activities. On the other hand, genetically acquired allergic conditions cannot be avoided.
According to world allergy organization (WAO), 18-30% of women in the childbearing age suffer from allergic diseases, with 20% of civilians suffering from rhinitis and asthma in USA. Proper diagnosis and management is necessary for avoiding serious allergic conditions in both mother and child.
In the same way, lifestyle modifications with exclusion of specific allergic triggering foods can aid in reducing the risk of foodborne allergies. So we can say correct diagnosis and treatment can alleviate the severity of life-threatening allergies and help with allergic relief.