That's a great questions! And as you can see from all of our answers, the use of antibiotics before clean surgery can vary among different physicians.
Antibiotics are use for two main reasons, to treat a current infections (therapeutic antibiotic use) and to minimize the risk of infection during surgery (prophylactic antibiotic use). In general, antibiotics are not necessary during clean surgery such as lipoma excisions in healthy individuals.
In the past, we use to routinely put patients on antibiotics prior to surgery. Many studies have found that prophylactic antibiotics before clean surgery on the skin is not necessary and does not reduce infection rates. In fact, when we put everyone on antibiotics before every surgery, we are more likely to have complications like antibiotic resistance, diarrhea, and allergies (such as in your case).
Several guidelines have been published in the literature about this issue. As long as the surgery site is not infected beforehand, there is really no need to give antibiotics for skin surgery in healthy patients. The overall rate of wound infection on skin surgery is less than 1%.
There are several times when I may consider antibiotics:
1. If surgery is done in certain areas: infected surgical site, lower legs, groin, lips, and ear-- because studies have shown these sites are more likely to get infected. I may also consider it if the surgery was very complicated.
2. If a patient has a prosthetic heart valve, heart transplant or congenital heart issues-- because if your wound were to get infected, it may spread to involve the heart valve.
3. If a patient had a recent joint replacement-- because if your wound were to get infected, it may spread to involve the prosthetic joint.
With that said, everyone is different and these are not hard and fast rules. I would trust your surgeon to help you make the best decision in your case.
Best,
Dr. Mann