All human beings as male or female have power to survive from outer factors . Our immunity system has to prevent the outer factor which effect our body. But some times these factors get inside our system and can disturb our system. This type of process is the main origin of allergy. 
Causes of Allergy:
In our daily life, allergy surrounds in our environment due to different reasons like plants, dust, soil, pet animal medicine and edible things .
- There can be same type of allergy to a family members by different things.
- Some has get a allergenic nature by touching flowers.
3.By taking milk, flesh, fish and egg - BY using polythene and nylon.
- Allergy can be occur by using cosmetics.
Some people found allergy by using of medicines. Besides these some chemical like cobalt, Nikel and cromium has the allergenic nature.
Characteristics of Allergy:
- Skin Itching or Pruritus
2.Skin getting red coloured
3.Red sport on skin. - Swelling on the effected place.
- After allergy a skin diseases Eczema can be occurs and there secrets some fluid also.
- Due to allergy some people influenced with bronchitis . people have to problem in breathing and suffer from nausea like diseases.
- acidity
8.swelling in face specially around eyes and on the lips. - feeling like vomiting.