After Negative Skin Testing

0 21
Avatar for BCH.Serg
1 year ago

Have you ever been hospitalized?

Your blood test showed that you have a bacterial infection and your physician ordered to start intravenous antibiotics. But before the nurse starts your antibiotic, he/she injects you a little amount on your outer canthus part of your forearm. Painful, right? That process is called Skin testing.

Some physician orders ANST ( ) after the end of the ordered antibiotics or some medication. So what is it, and why it is done?


ANST stands for "after negative skin testing." It is done to check if you have an allergy to any of the components of the medication. If it is tested positive, the medication will not be given to you and vice versa.

How it is done

The healthcare worker will fill up a 1 cc syringe with 0.9cc sterile water and will add 0.1cc of the diluted antibiotics. It is then injected to your outer part of the forearm to form a 1cm bleb. The bleb will now be encircled with a marker along woth the name of the medication, time when it is administered, and the time when will it be read.

It is usually read for any allergic reaction after 30 minutes or less if the patient complains of itchiness in the area where it is administered.

How to know when it is positive

A positive allergic reaction will show a bump, or redness that pass 2cm around the encircled bleb. And the most important thing is the subjective/verbal response of the patient. Didthe patient complained of itchiness around the affected area? If it is yes, the skin testing is positive.

What will happen if you are tested positive?

If you are tested positve on the skin test done, the physician might order other forms of iv antibiotics and it will be tested again. And if the results is still positive for the other antibiotic, you will be further be referred to an allergologist.


There are some certain exemptions that you won't need a skin test. This are:

  1. The physician wrote down "no need for skin testing"

  2. You are given the same kind of iv antibiotic in your previous hospitalization wherein you didn't positive for it

  3. The patient is 3 months old and below

ANST: Is it needed?

There are studies that there is no scientific based why the need of IV antibiotic skin testing if the person who will receive it is not allergic to any penicillin. But here in our country, Philippines, it is still practice for safety.

I've seen so many patients have an allergic reaction to antibiotics like rashes all over the body and difficulty of breathing.

For me, y doing skin tesing for allergies, it more provides the safety of both sides of the party. The patients health and the healthcare workers conscience.

$ 0.10
$ 0.05 from @Ruffa
$ 0.05 from @Kryptlook
Sponsors of BCH.Serg
Avatar for BCH.Serg
1 year ago