A 22-year-old woman presents with a 3-day history of bilateral sore throat, fever (38.5°C), and cervical lymphadenopathy. On examination, both tonsils are enlarged with yellowish-white exudate, and the pharynx is erythematous. There is no uvula deviation or intraoral bulge. She is able to swallow saliva and speak normally. Rapid streptococcal antigen test is positive. What is the most appropriate next step in management?