Generally, they are caused by an immune system which becomes hypersensitive after exposure to certain substances which it recognizes as harmful.
As a result of this exposure, the body's immune system releases huge amounts of antibodies to combat these "supposedly" harmful substances.
The release of these immune cells may then cause an adverse reaction in other cells within the body.
The substances are referred to as "allergens" and they can be anything from dust mites living in your carpet to pollen floating in the air.
Allergens are also encountered in pets, in particular, long haired animals.
With respect to skin allergies, they are generally problematic when the skin comes into contact with skin care products and other chemicals which contain allergens.
How Do Skin Allergies Work? When your bodies immune system discovers a substance which it views as harmful and potentially pathogenic it produces immunoglobulin G and IgM.
With the production of these agents, the immune system now becomes sensitized and attempts to neutralize the allergens, helping you to recover from the exposure.
Due to the initial exposure, your immune system is now ready to produce large amounts of antibodies next time it is exposed to the same substance.
This rapid build up of IgM allows you to recover from the exposure quickly and in some cases without any symptoms of allergy.
With skin allergies, on the other hand, allergens are dealt with slightly differently.
When an allergen, such as, as a cosmetic chemical come into contact with your skin for the first time, your immune system will start to automatically produce antibodies.
Except this time, instead of producing the standard IgM it will start manufacturing immunoglobulin E.
The immunoglobulin E will start to bind itself with the allergen and will attempt to neutralize the harmful agent, thereby prompting the sensitization process.
Without this process of sensitization, skin allergies can not occur.
As previously mentioned, as your body has been previously exposed to the obstructing agent your immune system is already sensitized to it.
Therefore, the next time you are exposed to this skin allergen your system will go into overdrive by producing IgE which will then attach themselves to the allergen and eventually the mast cells.
Mast cells are special cells which contain the main chemical involved in inflammation, foremost amongst them, are the chemical histamine.
As IgE is released within your body it causes the mast cells to release histamines into the surrounding tissue, causing widespread inflammation.
The typical reaction that you will view on the skin surface is called a wheal or a hive and is generally a fairly common symptom of skin allergies.
Types of Skin Allergies There are three main types of skin allergies: Contact Dermatitis Food Related Allergies Atopy Inhaled Dermatitis Skin allergies can also be caused by a range of food additives and ingredients such as pork, fish, eggs, chicken, soy, preservatives and dyes, dairy, and poultry products.
Contact dermatitis is categorized as occurring when your dermis (skin) comes into direct contact with allergens.
Typically, this is indicated by red swelling after touching flora or fauna such as poison ivy and ragweed.
It is common for young children playing outside to suffer from contact skin allergies.