4 doctors weighed in:

How can you tell if your baby is allergic to antibiotics? Is it possible to get an allergic reaction after 7 days of using it?

4 doctors weighed in
Dr. Martin Ostro
Internal Medicine - Allergy & Immunology
1 doctor agrees

In brief: History & exam fit

Allergic reaction to meds usually involves typical itchy rash (measles like or hives).
From first exposure to onset of reaction usually 7-10 days and on second exposure within minutes to hours. Get baby to experienced allergist who can examine baby and get detailed history. Except for penicillin there is no reliable skin testing for meds so history, exam are key. Take clear close-up pics of rash.

In brief: History & exam fit

Allergic reaction to meds usually involves typical itchy rash (measles like or hives).
From first exposure to onset of reaction usually 7-10 days and on second exposure within minutes to hours. Get baby to experienced allergist who can examine baby and get detailed history. Except for penicillin there is no reliable skin testing for meds so history, exam are key. Take clear close-up pics of rash.
Dr. Martin Ostro
Dr. Martin Ostro
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1 doctor agrees

In brief: Usually rash

For most people a rash will be the clue to an antibiotic allergy.
However, some rare patients can have a more severe reaction called anaphylaxis, which can be life threatening. The whole concept of "allergic" reaction requires exposure to a potential allergen and for the body's immune system to develop a sensitivity. This can happen after one dose or after many doses.

In brief: Usually rash

For most people a rash will be the clue to an antibiotic allergy.
However, some rare patients can have a more severe reaction called anaphylaxis, which can be life threatening. The whole concept of "allergic" reaction requires exposure to a potential allergen and for the body's immune system to develop a sensitivity. This can happen after one dose or after many doses.
Dr. Donald Shenenberger
Dr. Donald Shenenberger
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