Final answer:
In the case of a penicillin allergy, a peritonsillar abscess should be treated with alternative antibiotics such as macrolides or fluoroquinolones, and potentially surgical drainage if severe.
Step-by-step explanation:
The treatment of a peritonsillar abscess in a patient with a penicillin allergy would involve the use of alternative antibiotics to which the patient is not allergic. Since penicillin is often the first choice for treating this condition, alternative antibiotics such as macrolides (e.g., erythromycin) or fluoroquinolones may be prescribed in the case of a penicillin allergy. It's important to choose an antibiotic that is effective against the specific pathogen causing the infection, which can usually be determined through a culture or other diagnostic tests. In more severe cases, surgical drainage of the abscess may also be necessary, in addition to antibiotic therapy.