Allergy Diagnosis

Allergy is the most common disorder known to man. It is the disorder in which the immune system overtly becomes very sensitive to certain normally harmless substances. So, when the immune system comes in contact with such substances, known as allergens, it causes the activation of the antibody IgE(Immunoglobulin E) resulting in extreme inflammatory response. In severe cases it can even cause anaphylactic reactions and possibly death. A fifteen year old girl who was allergic to peanut died after kissing her boyfriend who had eaten peanut butter sandwich hours before. This will give you an idea of how severe allergies can be. If allergy to peanuts seems hard to believe then you will be surprised to know that many people also suffer from allergy to dust and pollen and even bee stings along with a host of other substances. Thus, allergy can make some people break out in violent rashes on being stung by a bee which the others can effectively heal with any ointment, or cause inflammation of the nasal passageway due to dust or pollen. Also, various types of foods, most commonly dairy products, cause a wide range of allergies. Since, there are a wide range of substances that can cause allergies it must be diagnosed correctly as the wrong diagnosis can prove to be very detrimental. One difficulty is that since the symptoms overlap and is also different for different individuals the diagnosis cannot be simply made on physical examination. Proper diagnosis can only be made when a variety of tests point towards a particular suspect. Read below to know the various methods by which allergies are diagnosed.

 

Medical History
It is absolutely necessary to understand the medical history of the patient to diagnose the type and form of allergy. The main technique to find this is through a questionnaire. The physician should also study the personality qualities of the patient.  This will help in interpreting the medical history of the patient. To avoid misdiagnosis the physician should address the complaint of the patient rather than what the patient thinks he or she is allergic to. 

The Complaint
The diagnosis should start from the main complaint of the patients that is what the symptoms are. All the symptoms are then listed and addressed according to the severity. 

Present Illness
First, the history of the present illness should be obtained and the details of each complaint must be gathered. Even mild and trivial symptoms must be jotted down. The physician must also find out the cause, time of onset, the geographical location, the season, and the circumstance of the symptoms. 

Family History
The allergy trait is inherited though not the specific sensitivity to a particular allergen. If parents and siblings are suffering from allergy then it can point towards allergy in the patient but it can be inaccurate too. The physician should know if there is any immunodeficiency disorders and cystic fibrosis disorder in the family. 

Physical Examination
The physical examination should be based on that of the patient’s complaints. It should also take into account various factors like the age of the patient. In adults, vital signs like height and weight must be taken into account. The physical examination should concentrate on the eyes, nose, sinuses, oropharynx, ears, neck, chest, heart, abdomen, and skin.

Skin Testing
Skin testing is the best diagnostic tool in allergy. It can be used to confirm a particular allergen. Skin tests are used to determine the immediate hypersensitivity through IgE level and it is the best diagnostic technique to determine allergy. A positive skin test will reflect the presence of allergy. The number of skin tests to determine the allergy, varies according to the age of the patient and the allergens tested. Depending upon the situation the number of skin tests may vary from less than 20 to as many as 80. The various types of skin tests are: