Beta Blockers USMLE Step 1 Practice Question

A 29-year-old woman with a known history of seasonal allergic rhinitis presents to her primary care physician complaining of progressively worsening nasal congestion over the past several days. She reports using an over-the-counter oxymetazoline intranasal spray up to four times daily for the past 10 days, well beyond the recommended three-day maximum duration. She initially obtained significant relief within minutes of each application, but now notices that her nasal stuffiness returns within one to two hours of each dose and feels worse than before she started the medication. She denies fever, facial pain, purulent discharge, or recent upper respiratory infection. Vital signs are unremarkable: temperature 98.6°F, blood pressure 118/74 mmHg, heart rate 72 beats per minute. Physical examination reveals markedly edematous, erythematous nasal mucosa bilaterally without purulence or polyps. Which of the following best describes the phenomenon responsible for her symptoms?