What antibiotic is likely to cause red rashes in patients who are informed to be taking it for a dental infection?

Penicillin is associated with a specific type of adverse reaction known as a drug rash, which can manifest as red rashes in some patients. This reaction often occurs in individuals who may have a sensitivity to the antibiotic or have previously experienced allergic reactions.

When Penicillin is used for treating dental infections, some patients may develop a maculopapular rash, which is a common reaction. This is particularly notable in patients who have underlying viral infections, such as Epstein-Barr virus, where the interaction with Penicillin can lead to a rash even in those who are not strictly allergic to the medication.

Other antibiotics, such as Erythromycin and Amoxicillin, can also cause rashes but are less commonly associated with this particular type of reaction in the context of dental infections. Ciprofloxacin may have its own set of adverse effects but is not typically linked to red rashes in the same way Penicillin is. Therefore, in the context of this question, Penicillin is the most likely candidate to cause red rashes in patients being treated for dental infections.