Allergic Reaction-Types,Causes,Prevention,Medicines.

allergic reaction

Allergic Reaction-Types,Causes,Prevention,Medicines.

Allergic reaction is a disturbance that affects only certain persons when they are exposed to things that they are sensitive to. It could come from :

  • Breathing in
  • Eating
  • Injection
  • Touch on the skin



Allergic reactions can be mild or very serious; they include :

  • Itching rashes, lumpy patches or hives.
  • Runny nose and itching or burning eyes (hay fever).
  • Irritation in the throat, difficulty breathing or asthma.
  • Allergic shock
  • Diarrhea (in children allergic to milk- a rare cause of diarrhea)

An allergy is not an infection and cannot be passed from one person to another. However, children of allergic parents also tend to have allergies.

Often, allergic persons suffer more in certain seasons or whenever they come in touch with the substances that bother them.



  • Pollen of certain flowers and grasses.
  • Chicken feathers.
  • Dust.
  • Kapok or feather pillows.
  • Certain medicines especially injections of penicillin, ampicillin or horse serum antitoxins.
  • Hair from cats and other animals.
  • Moldy blankets or clothes.
  • Bats
  • Specific foods especially fish, shell fish, beer etc.

The risk of a serious reaction is greater in a person who has previously been injected with one of these antitoxins or penicillin or with another medicine of the same group.



  • Use injections only when absolutely necessary. It is safer under medical supervision.
  • Before injecting one of the horse serum, ampicillin or penicillin, always have ready 2 ampules of adrenalin and an ampule of an antihistamine like promethazine (phenergan) or diphenhydramine (Benadryl).


  • Before injecting, always ask if at any other time a similar injection caused itching or other reactions. If the person says yes, do not use the medicine or any other medicine of the same group, either injected or taken by mouth.


  • In very serious cases like tetanus or snakebite, if there is a good chance that the antitoxin might produce an allergic reaction (if the person suffers from allergies or asthma or has had horse serum before), inject the antihistamine 15 minutes before giving the antitoxin. Promethazine dosage : For adults -25 to 50 mg, For children-6 to 25 mg depending on their sizes.


  • After injecting any medicine, always stay with the person for 30 minutes to watch for any of the following signs : cool, moist, pale, gray skin (cold sweat), weak, rapid pulse or heartbeat, difficulty breathing, loss of consciousness.


  • If these signs appear, immediately inject Adrenaline : For Adults-1/2 ml, For children 1/4 ml.  Treat the person for shock, follow by giving an antihistamine.



  • Saline sinus rinse.
  • Nasal decongestants.
  • Antihistamine.
  • Anaphylaxis is used for anaphylactic reactions.
  • Corticosteroids.