types of allergy
Indoor Allergies
Houses and apartments can lodge a large number of allergens (house dust mites, mould, etc.), which can
cause allergies all year long.of these orders. While allergies are frequently considered as seasonal, our homes can lodge a vast array of allergens which can cause allergies all year long. Indoor allergies cause symptoms ranging from psychological symptoms (fatigue, irritability, poor sleep, negative effect on concentration and performance), allergic conjunctivitis (itchy, red and watery eyes), allergic rhinitis (sneezing, blocked or runny nose, swelling and itching in the oral area) to allergic asthma with dry cough and shortness of breath.
The most common indoor allergens include:
House dust mites
House dust mites, which are part of the spider family, measure between 0.2-0.4mm and are present in
all households where they tend to be more numerous in bedding, upholstery, carpets, etc.
House dust mites are one of the major causes of allergic rhinitis with symptoms such as congestion,
sneezing, a dry cough or bronchitis which can lead to asthma. House dust mite allergies are perennial.
Allergic rhinitis currently affects more than 500 million people worldwide. Patients with allergic rhinitis
are three times more likely to develop asthma than other people, and the risk for patients with house
dust mite-induced allergic rhinitis is about six times higher than those whose allergic rhinitis is caused by
grass pollen.
Pets
Allergies to cats are the most common type of allergy to dander. And represent two thirds of allergies to pets. Contrary to common belief, what triggers an allergic isn’t pet hair but a substance (Fel d 1) found on the pet’s fur.
This protein (or allergen) is produced by the skin of felines and is also present in their saliva, urine, tears and dander. The allergen can be found throughout homes, in bedding, upholstery, rugs and is suspended in the air. Cat hair can also be transported by clothes and shoes. The allergen can be found in significant quantities even in a home with no cat, in class rooms for example. Individuals allergic to cat can inhale significant quantities of the protein without even knowing it and children with a predisposition towards allergies can be sensitized to cats without being in direct contact with one. Sensitization to dogs is less common that cat allergies. As with cats, the allergenic protein (Can f 1) is present on dog fur but is less allergenic.
Other pets can also trigger allergic reactions:
- Rodents: guinea pigs, hamsters, mice, rats and rabbits
- Exotic pets: gerbils, chinchilla, reptiles, arachnids, amphibians
- Birds: parrots, canaries, parakeets
- Farm animals: cows, horses, goats, sheep
Mould
Mould is composed of microscopic fungi that are present in the environment. Fungi can be found both
indoors in damp areas (bathroom, kitchen, etc.) and outdoors (fallen leaves, compost, grasses, etc.). The
spores released by the fungi can be carried by wind and dew. Mold can also develop on foods (bread,
cheese, fruit and vegetables).
The microscopic size of fungi spores, which ranges from 3 to 10µm), enables them to easily penetrate
the respiratory tract.
Mould can trigger respiratory allergies, both on a seasonal and perennial basis, such as allergic rhinitis,
conjunctivitis and asthma
The most common moulds which trigger allergic reactions are:
• Alternaria alternata (indoor and outdoor mold)
• Penicillium and cladosporium (which are present outdoors but predominant indoors)
• aspergillus: a type of mold which can trigger immediate reactions (sneezing, cough, skin rash) as
well as more critical reactions such as pulmonary aspergillosis (pulmonary disease
Outdoor Allergies
Seasonal allergic rhinitis affects millions of people. Symptoms range from a runny nose and congestion to allergic asthma. Seasonal allergic rhinitis affects millions of people around the world. Seasonal allergies cause symptoms such as allergic conjunctivitis (itchy, red and watery eyes), allergic rhinitis (sneezing, blocked or runny nose, swelling and itching in the oral area) psychological symptoms (fatigue, irritability, poor sleep, negative effect on concentration and performance) and allergic asthma with a dry cough and shortness of breath.
Seasonal allergens include:
Pollen
Pollens are suspended in the air on sunny and warm days, they can be carried by the wind over several kilometers. The amount of pollen ion the atmosphere is lower on rainy days as well as on cold and humid days. Pollens responsible for respiratory allergies come from three categories:
Trees
Tree pollen which can trigger allergies include:
The Betulaceae family (birch)
• The Fagaceum family (beech, oak)
• The Oleacceae family (ash, olive tree)
Grasses
The Poaceae (grass) family includes more than 12,000 different species. Grasses are found in gardens, lawns, forests as well as on water or on rocks. Even a tiny concentration of grass pollen is enough to trigger an allergic reaction. Fodder and cereal grasses which can trigger allergies include: dactylic (cocksfoot or orchard grass), timothy, sweet vernal, ryegrass and bluegrass. In the Northern hemisphere their pollination period extends from March to September with peaks in May, June and July.
Weeds
Species from the herbaceous family have soft and supple stems. Their pollens, which are small and light, can remain suspended in the atmosphere for a long period of time and can be carried over long distances. Herbaceous weeds which can trigger an allergic reaction include: mugwort, nettle, lamb’s quarters, ragweed, sage, Russian thistle… Aromatic plants such as lemongrass, tarragon, and wormwood are part of the same family (Asteraceae). Their pollination season in the Northern hemisphere goes from March to September with peaks in July, August and September.
Mould
Fungi can be found both outdoors (fallen leaves, compost, grasses, etc.) and indoors in damp areas (bathroom, kitchen, etc.). The spores released by the fungi can be carried by wind and dew. The microscopic size of fungi spores, which ranges from 3 to 10µm), enables them to easily penetrate the respiratory tract. Mould can trigger respiratory allergies, both on a seasonal and perennial basis, such as allergic rhinitis, conjunctivitis and asthma.
The most common moulds which trigger allergic reactions are:
• Alternaria alternate (indoor and outdoor mold)
• Penicillium and cladosporium (which are present outdoors but predominant indoors)
• aspergillus: a type of mold which can trigger immediate reactions (sneezing, cough, skin rash) as
well as more critical reactions such as pulmonary aspergillosis (pulmonary disease)
Solutions
Our solutions
Allergic rhinitis - popularly known as hay fever - is a widespread chronic disease.
Allergic Conjunctivitis
What is Allergic Conjunctivitis?
Allergic conjunctivitis is one of the most common and treatable eye conditions in children and adults. Often called “pink eye,” it is an inflammation of the conjunctiva, the tissue that lines the inside of the eyelid and the white of the eyeball, and helps keep the eyelid and eyeball moist. Allergic conjunctivitis is
not contagious
What are the triggers of Eye allergy?
Allergens that may be present indoors or outdoors can cause eye allergies. The most common outdoor airborne allergens are grass, tree and weed pollens. People who are sensitive to these allergens suffer from seasonal allergic conjunctivitis, the most common type of eye allergy. Pet hair or dander, dust mites and moulds are the most common indoor allergens. These indoor allergens can trigger symptoms for some people throughout the year, resulting in perennial allergic conjunctivitis. Cigarette smoke, perfume and diesel exhaust may inflame your eyes. They can act as irritants that cause non-allergic symptoms, or they can make your allergic response worse.
What are the types of Allergic Conjunctivitis?
Allergic conjunctivitis may be divided into 5 major subcategories.
Seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC) are commonly grouped together in Mild acute Allergic conjunctivitis or Hay Fever Conjunctivitis. Vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis (AKC), and giant papillary conjunctivitis (GPC) constitute the remaining subtypes of allergic conjunctivitis, and are grouped together in Chronic Conjunctivitis.
1. Seasonal Allergic Conjunctivitis & Perennial Conjunctivitis
Seasonal allergic conjunctivitis occurs at the same time each year.Most cases are due to pollen and occur in the hay fever season.Symptomstend to last a few weeks each year and may vary withthe pollen countperennial conjunctivitis is a conjunctivitis that persists throughout the year (perennial means through the year). This is most commonly due to an allergy to house dust mite
2. Allergies to Animals
Coming into contact with some animals can cause allergic conjunctivitis. This is usually due to allergy to fur or hair.
3. Vernal Kerato Conjunctivitis
VKC is a chronic bilateral inflammation of the conjunctiva, commonly associated with a personal and/or family history of atopy. More than 90% of patients with VKC exhibit one or more atopic conditions, such as asthma, eczema, or seasonal allergic rhinitis.
4. Giant Papillary Conjunctivitis
This is uncommon. It is an inflammation of the conjunctiva lining the upper eyelid. It occurs in some people who have a small object on the eye – most commonly, a contact lens. It affects about 1 in 100 wearers of contact lenses. The exact cause of the inflammation is unclear -it is possibly an allergic reaction to debris caught behind a lens or to poor lens hygiene. It also sometimes develops after eye surgery.
5. Atopic Kerato Conjunctivitis
AKC is a bilateral inflammation of conjunctiva and eyelids, which has a strong association with atopic dermatitis. It is also a type I hypersensitivity disorderwith many similarities to VKC, yet AKC is distinct in a number of ways. Atopic dermatitis is a common hereditary disorder that usually has its onset in childhood;symptoms may regress with advancing age. Approximately 3% of the populationis afflicted with atopic dermatitis, and, of these, approximately 25% have ocular involvement.
6. Contact Conjunctivitis
Some people become sensitised to cosmetics, make-up, eye drops or other chemicalsthat come intocontact with the conjunctiva. This then causes an allergic response and symptoms of conjunctivitis. In this condition the skin on the eyelids may also become inflamed. It is then called contact dermatoconjunctivitis.
What are the Symptoms of Allergic Conjunctivitis?
- Itching
- Stringy or ropy discharge
- Redness of eyes
- Teary eyes with a watery discharge
- Burning
- Stinging
- Mild sensitivity to light (Photophobia)
Food allergy :
Food Allergy is an abnormal response of immune system triggered by food. Most of the reactions are IgE mediated. It can involve skin, gastrointestinal tract, respiratory tract and in severe cases cardiovascular. Manifestations may happen immediately post ingestion, though in some cases it may
take hours to days.
What is Food Intolerance?
Food intolerance or non-allergic food hypersensitivity is a term used widely for varied physiological responses associated with a particular food, or compound found in a range of foods. Food intolerance is a detrimental reaction, often delayed, to a food, beverage, food additive, or compound found in foods that produces symptoms in one or more body organs and systems, but it is not a true food allergy. A true food allergy requires the presence of immune mechanisms (as for instance Immunoglobin E – IgE antibodies) against the food, and food intolerance does not.
How Food Allergies Work?
Food allergies involve two features of the human immune response. One is the production of immunoglobulin E (IgE), a type of protein called an antibody that circulates through the blood. The other is the mast cell, a specific cell that occurs in all body tissues but is especially common in areas of the body that are typical sites of allergic reactions, including the nose and throat, lungs, skin, and gastrointestinal tract. The ability of a given individual to form IgE against something as benign as food is an inherited
predisposition. Generally, such people come from families in which allergies are common — not necessarily food allergies but perhaps hay fever, asthma, or hives. Someone with two allergic parents is more likely to develop food allergies than someone with one allergic parent. Before an allergic reaction can occur, a person who is predisposed to form IgE to foods first has to be exposed to the food. As this food is digested, it triggers certain cells to produce specific IgE in large amounts. The IgE is then released and attaches to the surface of mast cells. The next time the person eats that food, it interacts with specific IgE on the surface of the mast cells and triggers the cells to release chemicals such as histamine. Depending upon the tissue in which they are released, these chemicals will cause a person to have various food allergy symptoms. If the mast cells release chemicals in the ears, nose, and throat, a person may feel an itching in the mouth and may have trouble breathing or swallowing. If the affected mast cells are in the gastrointestinal tract, the person may have abdominal pain, vomiting, or diarrhoea. The chemicals released by skin mast cells, in contrast, can prompt hives.
Symptoms
An allergic reaction to food can affect the skin, the gastrointestinal tract, the respiratory tract, and, in the most serious cases, the cardiovascular system. Reactions can range from mild to severe, including the potentially life-threatening condition known as anaphylaxis. Symptoms typically appear within minutes to several hours after eating the food to which you are allergic. Keep in mind that children may communicate their symptoms in a different manner than adults.
Mild symptoms may include one or more of the following:
- Hives (reddish, swollen, itchy areas on the skin)
- Eczema (a persistent dry, itchy rash)
- Redness of the skin or around the eyes
- Itchy mouth or ear canal
- Nausea or vomiting
- Diarrhea
- Stomach pain
- Nasal congestion or a runny nose
- Sneezing
- Slight, dry cough
- Odd taste in mouth
- Uterine contractions
Severe symptoms may include one or more of the following:
- Obstructive swelling of the lips, tongue, and/or throat
- Trouble swallowing
- Shortness of breath or wheezings
- Turning blue
- Drop in blood pressure (feeling faint, confused, weak, passing out)
- Loss of consciousness
- Chest pain
- A weak or “thread” pulse
- Sense of “impending doom”
Food Allergen
Although nearly any food is capable of causing an allergic reaction, only eight foods account for 90 percent of all food-allergic reactions
Common Food Allergens
- Peanut
- Tree nuts
- Milk
- Egg
- Wheat
- Soy
- Fish
- Shellfish
Drug Allergy:
Drug allergies are a group of symptoms caused by an allergic reaction to a drug (medication). The chances of developing an allergy are higher when you take the medication frequently or when it is rubbed on the skin or given by injection, rather than taken by mouth.
Causes
Adverse reactions to drugs are common. Almost any drug can cause an adverse reaction. Only about 5% to 10% of these reactions are due to an allergy to the medication. Reactions range from irritating or mild side effects such as nausea and vomiting to life-threatening Anaphylaxis. A true drug allergy is caused by a series of chemical steps in the body that produce the allergic reaction to a medication. The first time you take the medicine, you may have no problems. However, your body’s immune system may produce a substance (antibody) called IgE against that drug. The next time you take the drug, the IgE tells your white blood cells to make chemical called histamine, which causes your allergy symptoms. A drug allergy may also occur without your body producing IgE. Instead, it might produce other types of antibodies, or have other reactions that do not produce antibodies. Most drug allergies cause minor skin rashes and hives. Serum sickness is a delayed type of drug allergy that occurs a week or more after you are exposed to a medication or vaccine.
Penicillin and related antibiotics are the most common cause of drug allergies.
Other common allergy-causing drugs include:
- Anticonvulsants
- Aspirin and non-steroidal anti-inflammatory medications, such as ibuprofen
- Insulin (especially animal sources of insulin)
- Iodinated (containing iodine) x-ray contrast dyes (these can cause allergy-like reactions)
- Sulfa drugs
- Chemotherapy
Most side effects of drugs are not due to an allergic reaction. For example, aspirin can cause nonallergic
hives or trigger asthma. Some drug reactions are considered “idiosyncratic.” This means the reaction is
an unusual effect of the medication, not due to a predictable chemical effect of the drug. Many people
confuse an uncomfortable, but not serious, side effect of a medicine (such as nausea) with a true drug
allergy, which can be life threatening. If you take ACE (angiotensin converting enzyme) inhibitors for
high blood pressure, you may develop a cough or facial and tongue swelling.
- Hives
- Itching of the skin or eyes (common)
- Skin rash (common)
- Swelling of the lips, tongue, or face
- Wheezing
Anaphylaxis:
Anaphylaxis is serious, potentially life threatening allergic reaction. It can occur within seconds or minutes of exposure to something you’re allergic to, such as insect bites, foods, and medications.
Symptoms
Generalised flushing of the skin
- Nettle rash (hives) anywhere on the body
- Sense of impending doom
- Swelling of throat and mouth
- Difficulty in swallowing or speaking
- Alterations in heart rate
- Severe asthma
- Abdominal pain, nausea and vomiting
What can cause Anaphylaxis?
Common causes include
- Foods such as peanuts, tree nuts (e.g. almonds, walnuts, cashews, and Brazil nuts), sesame, fish, shellfish, dairy products and eggs.
- Insect bites Non-food causes include wasp or bee stings, natural latex (rubber), penicillin or any other drug or injection.
- Medications both over the counter and prescribed, can cause life threatening allergic reactions.
- Individuals can also have anaphylactic reactions to herbal or ‘alternative’ medicines
- Others in some people, exercise can trigger a severe reaction – either on its own or in combination with other factors such as food or drugs (e.g. aspirin).
