Food allergies:

Food allergies are different from food fads. Certain fds  seem to have strange reactions on some people. Probably, you have come across a person who got skin rashes everytime he ate eggs. Certain substances in food cause "allergy" to some people. Allergy is  the scientific name given to a disturbance which arises when a person is sensitive to a substance. Some people are  allergic to pollen, others are  allergic to skin-contact with  some materials. Allergy to medicines is also common. In fact, before giving a penicillin injection, doctors first test whether the patient is allergic to it. Foods which cause allergies are, fish, eggs, milk and milk products. Substances that cause allergy are protein in nature. Food allergies are  manifested in the form of  skin rashes, skin eruption called  eczema. asthma, frequent sneezing, one-sided severe headache called migraine, vomiting, diarrhoea, etc.