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A 33-year-old member asked:

my doc gave me keflex to take prior to an upcoming procedure but im alergic to penecilian (sp). should i be concerned about a possible reaction?

1 doctor answer1 doctor weighed in
Dr. Ralph Morgan Lewis
Family Medicine 38 years experience
Maybe: Reportedly about 10% of penicillin-allergic patients will also be allergic to Keflex or other cephalosporins. If you develop a rash or difficulty breathing on penicillin, you should probably ask your doc for an alternative antibiotic.

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Similar questions

A member asked:

Will my son's strange reaction following antibiotics last.

4 doctor answers11 doctors weighed in
Dr. Irwin Berkowitz
Specializes in Pediatrics
Yes: Allergic reactions to antibiotics, ie hives can last up to two weeks after stopping the medication. Antibiotic induced diarrhea can improve soon after discontinuing the antibiotics or linger. There are other nonspecific rashes that are not an allergy but an interaction between the antibiotic and a virus that can last for days. Behavioral reactions to colorings or flavors abate qickly.
A 21-year-old member asked:

Some of my patients describe having had a severe reaction to something they were given for tetanus many years ago. What could this be?

2 doctor answers3 doctors weighed in
Dr. James Ferguson
Pediatrics 46 years experience
If a child;pertussis: The formulation given to kids as DTP up to 1992 contained the whole cell preparaation for pertussis. This was an effective but problamatic vaccine, as 30% had fever by the 2nd dose and older kids were very sore. It wasn't given over 6y due to its many side effects. The acellular pertussis vaccine replaced it that year & has been remarkable in its lack of shot reactions.
A 42-year-old member asked:

Why do I have to take penicillin vk tablets before food?

1 doctor answer4 doctors weighed in
Dr. Alfredo Garcia
Pediatrics 56 years experience
Penicillin: Some medications are absorbed better in the absence of food and such is the case for penicillins.
A 33-year-old member asked:

What are the dangers of allergic reactions? My new housemate has a bunch.

1 doctor answer1 doctor weighed in
Dr. Jeffrey Rosch
Allergy and Immunology 49 years experience
Allergy symptom vary: Allergic reactions can vary from minimally annoying to fatal. If your housemate has more than mild nasal, eye, or skin symptoms i would suggest seeing a board certified allergist to define and appropriately treat the allergies.
A 39-year-old member asked:

How long do mosquito bite reactions happen?

1 doctor answer3 doctors weighed in
Dr. Michael Ekizian
A Verified Doctoranswered
A US doctor answeredLearn more
Duration?: Local pain, itching, and redness of the skin are typical after a mosquito bite. There is usually an immediate wheal and flare response that peaks at about 20 minutes, or a hard, itchy, bump that peaks at two to three days and resolves over the ensuing days to weeks.
Dr. Harold Peltan
Ophthalmology 28 years experience
Agree. And don't scratch it. It will take longer to resolve.
Sep 8, 2013

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Last updated Oct 3, 2016

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