Types of Allergy
Allergies come in a wide variety. They are often classified according to where they produce symptoms: skin, respiratory tract (nose, lungs). Or their causes: insect stings, foods, medicines.

  • Respiratory
  • Allergies to insect stings
  • Skin Allergies
  • Food Allergies
  • Allergies to medicine

Causes of Allergy
The substances that cause allergic disease in sensitized people are known as allergens. They enter our bodies in a variety of ways:

  • Inhaled into the nose and the lungs

Examples are: airborne pollens of certain trees, grasses and weeds, dust mite droppings, moulds spores, cat and dog dander

  • Ingested by mouth

These are generally the things that we eat and drink, including prawn and peanuts

  • Injected

Such as reactions to stinging insects and injectable drugs

  • Absorbed through the skin

Things we come into contact with: poison ivy, oak and cosmetics
asthma
The normal reaction of our body to invasion by foreign substances is to defend itself. This is the role of our immune system.
Hayfever (Seasonal Allergic Rhinitis)
should not really be called hayfever because it is caused by pollen and fungal spores not hay!
It is therefore more accurate to call it pollinosis or seasonal allergic rhinitis (symptoms occur only during the pollen season).

Pollen is the male part of the flower. It is made up of tiny grains with very different shapes, depending on the plant species. Some have prickles, others holes or slits. The average size is about 1/20 (0.05) mm across, which means they are invisible to the naked eye. Pollen grains contain a large number of allergenic proteins.

The main cause of hayfever are pollens dispersed by the wind as these are produced in large numbers to overcome the wastage. In contrast pollens carried by insects have a greater chance of reaching the target and as such do not become airborne, which mean they are less likely to cause allergic reactions.
Tree pollen Grass pollen
Cold or Allergy?
If you start to sneeze in the winter and keep on sneezing, you may think that you have a cold that just doesn’t seem to want to go away. However, you may be experiencing an allergic reaction to moulds or other winter allergens.

A cold is a common viral syndrome characterized by watery nasal discharge and a general feeling of ill health lasting approximately 7-10 days. Whereas an allergy tends to be continuous but sometimes goes and then returns.

Nasal allergic symptoms that don’t seem to want to go away, like congestion or runny nose and sneezing are frequently misdiagnosed as a permanent cold. A recent report by the Royal College of Physicians states that up to 3 out of 4 sufferers of these year round symptoms may actually have an allergy.

Reduced ventilation during the winter months exacerbates allergic reactions. Dust mites are a major cause of allergy and domestic pets are the second largest source of indoor allergens.

Frequent upper respiratory symptoms may point to undiagnosed allergies. The symptoms occur because the body responds to the minute, allergy-causing particles or allergens by producing mucus. Allergic triggers lead to stuffy, runny nose and sneezing. To alleviate your symptoms, you need to identify the allergens causing the reaction and eliminate them as much as possible from your environment.

However, when preventative measures fail it may be appropriate to control your symptoms using medication. Today antihistamines are generally considered the first-line treatment for allergy symptoms and are available by prescription or over the counter.
Dust Allergy
House dust allergy is common even in clean homes.

House dust is a major cause of year-round runny or stuffy nose, itchy, watery eyes and sneezing for allergy sufferers.

Dust can also make people with asthma experience wheezing, coughing and shortness of breath.

House dust is a mixture of many things. It varies from home to home, depending on the type of furniture, building materials, presence of pets, moisture and other factors.

A speck of dust may contain fabric fibers, human skin particles, animal dander, microscopic creatures called mites, bacteria, parts of cockroaches, mould spores, food particles and other debris.

Of these, animal dander, the house dust mite and cockroaches are the most common culprits.

A person may be allergic to one or more of these substances, and, if exposed to the dust, will have an allergic reaction.
Animals
Allergy to animals is very common and can make other allergies worse.

Pets are a major source of allergens. Although the allergens are not in the animals’ fur (contrary to what many people think), their coats can be very good “transporters” of allergens.

The allergen is often referred to as “dander”.

Animal danders are the most common nonseasonal, inhaled allergen. Animal danders may induce hay fever and asthma symptoms, or they may produce skin reactions such as urticaria.
Insect Stings
Severe allergic reactions can occur due to stings from Honey Bees, Wasps, Hornets or Yellow Jackets.
Bees
Bees are not naturally aggressive. They sting only when they feel threatened or when their nest is in danger.

A bee’s stinger is barbed and cannot be withdrawn when the skin is penetrated – a real miniature harpoon! In the bee’s struggle to escape, the stinger, poison gland, and some of the digestive tract are torn from its body, so the bee dies.
Wasps
Wasps (ordinary wasp and hornet) on the other hand, are naturally aggressive. They are particularly aggressive in the autumn, when their food runs out.

A wasp’s stinger is smooth (non-barbed) and can be easily withdrawn. A wasp therefore can sting again and again.
Skin Allergies
Red, bumpy, scaly, itchy, swollen skin….any of these symptoms can signify an allergic skin condition.

These skin problems can be caused by a range of different things: animals, plants, medicines, foods, or even your clothes.

There are a range of different types of skin allergies, and over the next few pages, we have provided information on some of the three most common problems:

  • Hives
  • Angieoedema
  • Eczema

Dealing With Allergies
Removal
The first measure to take is removal (eviction) of the allergen in question (after diagnosis, of course!). This is not always easy because of psychological associations (e.g. separating a child from a favorite pet) or sometimes even impossible (e.g. selling cheap xenical).

However, it should be possible to reduce the quantity of allergens (e.g. house dust) or even get rid of them (e.g. contact allergens).
Desensitization
It would in fact be accurate to use the term hyposensitization. This treatment does not completely suppress allergen sensitization, but it does make the patient less sensitive to allergens.