Which is not a common cause of hypersensitivity pneumonitis?

Correct Answer: D

Rationale: Dust mites are not a common cause of hypersensitivity pneumonitis, unlike moldy hay, bird droppings, humidifiers, and air conditioners.

Correct Answer: C

Rationale: Oral ulcers in Behcet's disease typically do not scar.

Correct Answer: A

Rationale: Eosinophilia is not typically associated with Giardia infection, but it is common in the other conditions listed.

Correct Answer: D

Rationale: Anaphylactic shock is a severe allergic reaction characterized by vasodilation, airway swelling, and circulatory collapse, requiring immediate epinephrine administration.

Correct Answer: A

Rationale: Squatting helps increase systemic vascular resistance, reducing the right-to-left shunt and improving oxygenation in Tetralogy of Fallot.

Correct Answer: B

Rationale: Approximately 25% of children with food allergies experience severe anaphylactic reactions, requiring immediate medical intervention.

Correct Answer: B

Rationale: L2 ALL is characterized by large, irregular blasts and is more common in adults.

Correct Answer: B

Rationale: Doxorubicin is a chemotherapeutic agent known for its dose-dependent cardiotoxicity, leading to dilated cardiomyopathy due to mitochondrial dysfunction and oxidative stress in cardiac myocytes.

Correct Answer: D

Rationale: Deforestation leads to the loss of biodiversity as it destroys natural habitats for countless species, disrupting ecosystems.