Causative & risk factors
Common triggers for anaphylaxis include:
Food: Such as milk, eggs, peanuts, shellfish, fish, wheat, soy and tree nuts are commonest.
Medications: such as penicillin, aspirin, ibuprofen, polymyxin, morphine, x-ray dye.
Insect bites and stings: such as bee, wasp and jack jumper ant sting are the commonest.
Clinical presentation
Symptoms of anaphylaxis may begin a few minutes or half hour after the patient comes into contact with the responsible allergen. The first symptoms are usually red rashes or hives all over the body that produce itching. Angioedema i.e. swelling beneath the skin may develop all over. There is usually a sensation of heat in the body along with anxiety or a sense of impending doom.
The patient’s throat may swell up causing difficulty in swallowing and hoarseness of voice. The chest muscles may become tightened leading to difficulty in breathing and wheezing. Gastro-intestinal symptoms such as vomiting, diarrhea or stomach cramps may be present. The patient may become dizzy or faint.
Investigations
Diagnosis is based on detailed medical history which may include any food or medications consumed before the anaphylactic reaction. The doctor will also enquire whether the patient suffered any insect bite prior to the reaction.
To confirm the diagnosis and find the substances you are allergic your doctor will suggest skin allergy test or blood allergy test.
Treatment
Anaphylaxis is an emergency medical condition and requires hospitalization. CPR (cardiopulmonary resuscitation) is performed if the patient stops breathing or his/her heart stops beating. An epinephrine injection is rapidly administered to reverse the anaphylactic symptoms. Intravenous fluids are oxygen are given if necessary. This is followed by administering other medications such as anti-histamines (for allergic symptoms), steroids (to reduce inflammation) and medications to restore the heart function and breathing back to normal.
Anaphylaxis can be fatal if timely treatment is not administered.
Once the acute episode is over, the patient is advised to avoid the responsible allergen altogether. Additionally, he must carry epinephrine with himself at all times so that it can be injected if another anaphylactic episode takes place.
