A 12-year-old presents to the clinic with his father for evaluation of a painful lump in the left eye. It started this morning. He denies any trauma or injury. There is no visual disturbance. Upon physical examination, there is a red raised area at the margin of the eyelid that is tender to palpation; no tearing occurs with palpation of the lesion. Based on this description, what is the most likely diagnosis?

Correct Answer: C

Rationale: The correct answer is C: Hordeolum. A hordeolum, also known as a stye, presents as a red raised tender area at the margin of the eyelid. In this case, the absence of tearing upon palpation of the lesion suggests it is localized to the eyelid itself. Dacryocystitis (choice A) involves the lacrimal sac and would present with tearing. A chalazion (choice B) is a painless nodule on the eyelid, unlike the tender lesion described here. Xanthelasma (choice D) is characterized by yellowish plaques on the eyelids, not a red raised tender area.

Correct Answer: C

Rationale: The correct answer is C: Efferent nerve damage on the right. When both pupils dilate but only the right pupil constricts briskly in response to light, it indicates a problem with the efferent pathway controlling the right eye's pupillary constriction. This suggests damage to the parasympathetic fibers of the oculomotor nerve (CN III) that innervate the pupillary sphincter muscle. Choices A and B (optic nerve damage) do not involve pupil constriction. Choice D (efferent nerve damage on the left) would not explain the brisk constriction in the right eye.

Correct Answer: D

Rationale: The correct answer is D because the 5th intercostal space is the recommended location for chest tube insertion to drain the pleural space effectively. This space is ideal as it allows for adequate drainage without causing injury to vital structures. A: The 2nd intercostal space is actually used for needle decompression in tension pneumothorax. B: T6 is the level at which the tip of the endotracheal tube should ideally lie to ensure proper placement and ventilation. C: The sternal angle corresponds to the 2nd rib, not the 4th rib, making this association incorrect. In summary, choice D is correct as it aligns with the standard practice for chest tube insertion, while choices A, B, and C are incorrect due to their association with different anatomic landmarks and procedures.

Correct Answer: D

Rationale: The correct answer is D: Examine him for tenderness over the injured area. Rationale: 1. Start with a physical examination to assess for tenderness directly over the injured area. 2. Rib fractures often present with localized tenderness upon palpation. 3. If tenderness is present, suspect a rib fracture and advise immobilization. 4. Advise against unnecessary movement to prevent further injury. Summary: - Choice A: Calling a medevac helicopter is premature without assessing the severity of the injury. - Choice B: Driving him 4 hours away could worsen his condition without proper assessment. - Choice C: Pressing on the sternum and spine simultaneously is not recommended as it can cause further harm.

Correct Answer: C

Rationale: The correct answer is C: Mitral valve defect. This is because the mitral valve is best heard in the left lateral decubitus position. In this position, the heart rotates, bringing the mitral valve closer to the chest wall, making it easier to auscultate any abnormalities such as murmurs. Aortic (A), pulmonic (B), and tricuspid (D) valve defects are not typically better heard in the left lateral decubitus position, so they are incorrect choices.