Medicine Allergies

Anyone can develop an allergy to pretty much anything at any time. Medicines are no different. 

Some people will develop an allergy to a medicine similar to a food allergy; after taking the medicine, a person can start having a rash with hives and itching. These milder symptoms should be helped by just not giving the medicine anymore and the possible use of an antihistamine like Benadryl/diphenhydramine. It is also possible to have more serious reactions that resemble anaphylaxis like swelling of the eyes, tongue, or lips; trouble breathing; and vomiting. If your kiddo is having or has had a more serious reaction, they should be seen by their pediatrician or in an emergency room for monitoring. 

Medicines can also cause reactions that are not technically allergies (not caused by IgE antibodies releasing histamine) but are more of a side effect. The most common one of these possibly allergy-looking side effects is the drug rash from penicillin antibiotics like amoxicillin. Some kids and adults will develop this rash that usually occurs on the 5th to 10th day of taking amoxicillin, but this rash won’t have hives or itch all that much. And the farther out one is from taking the medicine, the more the rash eases. This is not an allergic reaction and is considered more of a drug rash or possible drug reaction. This means that your pediatrician will probably not prescribe penicillin antibiotics for your kiddo anymore, but let’s say that your child comes down with a weird infection that can only be treated by antibiotics in the penicillin family, we can still give that child the medicine (with some possible pretreatments) to fight that infection without worrying about an anaphylactic reaction.