Also known as: AIDS
Kalvin is an HIV-positive patient who has progressed to AIDS. His case drives the episode as his new HIV medications cause his immune system to rebound strongly, initially suspected to cause immune reconstitution syndrome. His T-cell count had dropped to 30 but rebounded to 200 after changing medications.
Also known as: Parasitic cysts from fox hunting
The ultimate diagnosis for Kalvin's cardiac and pulmonary masses. The parasitic cysts were acquired from hunting foxes in Montana, forming masses in his heart and lungs that mimicked cancer. His father has the same condition with liver cysts.
Also known as: Parasitic cysts from fox hunting
Kalvin's father has hepatic cysts from the same parasite, initially misdiagnosed as cirrhosis. House deliberately ruptures a cyst to prove the diagnosis and force the father to receive treatment, causing anaphylactic shock.
Also known as: Severe allergic reaction
Kalvin experiences anaphylactic shock early in the episode, initially attributed to his HIV medication Abacavir. Later revealed to be related to his parasitic condition.
Also known as: Coughing up blood
Kalvin coughs up blood which gets into Cameron's eyes and mouth, creating a significant plot point about HIV exposure and post-exposure prophylaxis. The bleeding is later attributed to the parasitic cysts in his lungs.
Also known as: Fluid around the heart
Kalvin develops pericardial effusion with fluid crushing his heart, requiring emergency drainage. Initially thought to be blood, the fluid is clear, leading to discovery of the cardiac tumor/cyst.
Also known as: Mycoplasma infection
House's subplot involves diagnosing Stacy's rat with mycoplasmosis, a bacterial infection aggravated by cigarette smoke exposure. This parallel case helps House realize the parasitic nature of Kalvin's condition.
Also known as: Heroin addiction
Kalvin uses crystal meth and ecstasy as part of his Party and Play lifestyle. His drug use is initially investigated as a possible source of toxins causing his symptoms, and also represents his self-destructive behavior following his mother's death.