An allergy is an excessive or hypersensitive response of the immune system manifesting either as a pathological immune reaction induced by antibodies (immediate hypersensitivity) or by lymphoid cells (delayed type allergy). Instead of fighting off a disease-causing foreign substance, the immune system launches a complex series of actions against an irritating substance, referred to as an allergen

 

Types:

Hay fever:

Allergic rhinitis, also known as hay fever, is an allergic response to pollen or other microscopic substances

Urticaria:

It is a skin rash or dark red raised itchy bumps caused by viral allergies and also due to pressure, sunlight, temperature etc

Plant allergies:

• Poison ivy, poison oak, and poison sumac are plants that contain an irritating, oily sap called urushiol
• Urushiol triggers an allergic reaction when it comes into contact with skin, resulting in an itchy rash, which can appear within hours of exposure or up to several days later
• A person can be exposed to urushiol directly or by touching objects -- such as gardening tools, camping equipment

Insect sting allergies:

• Insects such as honeybees, yellow jackets, hornets, wasps, and fire ants
• While not everyone is allergic to insect venom, reactions in the skin such as mild pain, swelling, and redness may occur with an insect sting

Pet allergies:

• Pet allergy occurs when your immune system reacts to certain animal proteins
• This reaction triggers inflammation in the lining of your nasal passages causing sneezing, runny nose and other signs and symptoms usually associated with hay fever

Latex allergy:

• The protein in rubber can cause an allergic reaction in some people
• This reaction can range from sneezing to anaphylactic shock, which is a serious condition that requires immediate medical attention
• The thin, stretchy latex rubber in gloves, condoms and balloons is high in this protein. It causes more allergic reactions than products made of hard latex rubber (like tires)

Mold allergy:

• Mold is present in most indoor and outdoor spaces, and in many foods
• Overreaction of immune system when you breathe in mold spores
• This reaction triggers a cascade of reactions that lead to allergy symptoms like cough, itching of the eyes and cause other symptoms that make you miserable
• In some people, mold allergy is linked to asthma and exposure causes restricted breathing and other airway symptoms

Cosmetic allergies:

• Products such as moisturizers, shampoos, deodorants, make-up, colognes, and other cosmetics have become part of our daily grooming habits
• Although cosmetics can help us feel more beautiful, they can cause skin irritation or allergic reactions
• Certain ingredients used in cosmetics, such as fragrances and preservatives, can act as antigens triggering an allergic reaction

Drug allergies:

• Drug allergies are a group of symptoms caused by allergic reaction to a drug
• Adverse reactions to drugs are common, and almost any drug can cause an adverse reaction
• Reactions range from irritating or mild side effects such as nausea and vomiting to life-threatening anaphylaxis
• 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 exposure to a medication or vaccine
• Sulfa drugs, Anticonvulsants, Insulin preparations (particularly animal sources of insulin), Iodinated (containing iodine) x-ray contrast dyes

Eczema:

• This itchy skin rash, common in children and infants, affects some people all their lives
• Eczema is a general term for many types of skin inflammation, also known as dermatitis. The most common form of eczema is atopic dermatitis
• The exact cause of eczema, but an abnormal function of the immune system is believed to be a factor. Some forms of eczema can be triggered by substances that come in contact with the skin, such as soaps, cosmetics, clothing, detergents, jewelry, or sweat

Eye allergies:

• Allergic reactions involving the eyes being a common complaint
• An allergic reaction that affects the conjunctiva, a clear layer of skin overlying the eyes, is commonly referred to as allergic conjunctivitis
• Common allergens include: Pollen, Grass, Weeds, Dust and Pet dander

Milk allergy:

Many unsuspecting products contain milk or milk products. Milk protein causes allergy in some individuals. Those who have allergy to milk develop, vomiting, loose motions, abdominal cramps immediately after consuming milk

Food allergy:

• A food allergy is an exaggerated immune response triggered by eggs, peanuts, milk, or some other specific food
• The cause of food allergies is related to your body making a type of allergy-producing substance called immunoglobulin E (IgE) antibodies to a particular food
• Although many people have a food intolerance, food allergies are less common. In a true food allergy, the immune system produces antibodies and histamine in response to the specific food.
• Any food can cause an allergic reaction, but a few foods are the main culprits. In children, the most common food allergies are to: Eggs, Milk, Peanuts, Shellfish (shrimp, crab, lobster, snails, and clams), Soy, Tree nuts and Wheat.