The team first suspects an allergy to her boyfriend's semen, or perhaps unprescribed antibiotics he was taking, which could have been passed during their encounter.
The sixteenth episode of Season 2, titled " Safe ," first aired on April 4, 2006. It features a high-stakes medical mystery involving an immunocompromised teenage girl and a comedic subplot centered on the "odd couple" living arrangement between House and Wilson. Episode Summary
In a "race-against-the-clock" climax, House discovers the true culprit: a common wood tick lodged in an inconspicuous place on her body. The tick was secreting a neurotoxin causing her paralysis and heart issues. Memorable Moments & Subplots
Trachtenberg reportedly had a crush on Hugh Laurie during filming and hid an "I Love You" note under the modesty sheet during the scene where House examines her.
As her condition worsens, she experiences and a heart attack, leaving the team baffled because no single condition seems to link anaphylaxis with heart failure. The Diagnosis & Resolution
Michelle Trachtenberg's performance was so well-received that she was considered for an Emmy nomination for this guest role.
Dr. Foreman incorrectly explains how blood components settle in a centrifuge; in reality, red cells are the heaviest and settle at the bottom, not white blood cells.