When the immune system of a person overreacts to something and considers it dangerous, then it releases histamine, a chemical to counteract it. These substances are harmless to most of the people but trigger a reaction in response to anyone who is sensitive to it. This substance is known as the allergen. Allergies can be perennial or seasonal.

Causes of Allergies

There are some of the common allergy triggers including -

1. Certain food items such as fish, eggs, milk, peanuts, wheat, and shellfish

2. Insect stings

3. Airborne allergens such as dust mites, mold, animal dander and pollen

4. Immune system disorders

5. Medications

6. Infections

7. Stress

Symptoms of Allergies

  • Skin Rash

  • Headache

  • Sneezing

  • Swelling

  • Runny Nose

  • Nausea

  • Diarrhea

There are many types of Allergy:

1. Atopic Dermatitis (Eczema)

2. Hives (Urticaria)

3. Angioedema

Atopic Dermatitis (Eczema)

Eczema is the most common type of skin condition that is found in infants and children. It affects one in five infants but around one in fifty adults. Eczema is not contagious and is caused due to leakiness of the skin barrier which makes our skin dry and it becomes severe over time if not treated. It is more likely to be caused by both genetic and environmental factors and is often linked with asthma, food allergy, or allergic rhinitis (hay fever).


An inflammation of the skin, triggered when the immune system of the body releases histamine. Releasing of histamine causes small blood vessels to leak, resulting in swelling of the skin.

There are two kinds of urticaria, as follows:

1. Acute Urticaria- This type of Urticaria occurs when a person comes in contact with a particular trigger and the body releases histamine. There can be causes which are non-allergic and trigger urticaria such as heat or exercise, as well as medications, foods, insect bites or infections.

2. Chronic urticaria – Specific triggers or allergens causes chronic urticaria. It lasts for many months or years. It is painful and often uncomfortable. It’s not contagious.


1. Acute Angioedema

It lasts for the short period of time such as from few minutes to hours. A common cause for acute angioedema is certain medications and food items that respond in the form of allergic reaction.

2. Chronic Angioedema

There are no identified causes that are responsible for this type of allergy. Chronic recurrent angioedema is when the condition(skin allergy) returns over a long period of time.

3. Hereditary angioedema (HAE)

This is a serious genetic condition that involves swelling in various parts of the body including the feet, hands, face, intestinal wall, and airways. It is not common and does not respond to antihistamines, so it’s very important to get the treatment from a skin specialist.