Correct Answer: C

Rationale: The correct answer is C: Erythematous scaly patch with sharp margins in the sacral area. In patients with AIDS, this presentation is most likely indicative of a common opportunistic infection called tinea corporis. This fungal infection often presents as erythematous scaly patches with well-defined borders. The location in the sacral area is also common due to the warm and moist environment. Choice A, tinea capitis, is a fungal infection of the scalp and is not typically associated with AIDS. Choice B describes a presentation more indicative of a condition like seborrheic dermatitis rather than an AIDS-related skin manifestation. Choice D describes a presentation more typical of tinea corporis, which is not commonly seen in the axilla region in patients with AIDS.

Correct Answer: B

Rationale: The correct answer is B: a hordeolum (stye). A hordeolum is a localized infection in the eyelid, typically caused by bacterial infection of the oil glands. In this case, the presence of a painful pustule at the lid margin, along with redness and swelling, is characteristic of a hordeolum. The pain on touch is also indicative of an infection. Choice A, a chalazion, is an inflammatory lesion caused by a blocked oil gland, but it is usually painless and not typically associated with redness or tenderness. Choice C, dacryocystitis, is an infection of the lacrimal sac, which presents with different symptoms such as tenderness over the inner corner of the eye and tearing. Choice D, blepharitis, is inflammation of the eyelid margins, but it does not typically present with a painful pustule at the lid margin.

Correct Answer: B

Rationale: The correct answer is B: the patient can read at 6.1 m (20 ft) what a person with normal vision can read at 9.1 m (30 ft). This is because the Snellen notation 20/30 means that the patient can read at 20 feet what a person with normal vision can read at 30 feet. This ratio signifies the patient's visual acuity compared to a person with normal vision. The other choices are incorrect as they do not accurately interpret the Snellen notation or misinterpret the distance at which the patient can read the eye chart.

Correct Answer: A

Rationale: The correct answer is A: Heart failure. In this case, the most likely cause of the bilateral pitting edema in the lower legs is heart failure. The pitting edema along with the history of hypertension and coronary artery disease suggests fluid overload due to the heart's inability to pump effectively. The normal skin color, absence of redness or tenderness, and strong peripheral pulses indicate that the edema is not caused by venous thrombosis, local inflammation, or blockage of lymphatic drainage. In heart failure, fluid can accumulate in the lower extremities due to the heart's reduced ability to pump blood efficiently, leading to increased pressure in the veins and subsequent fluid leakage into the surrounding tissues.

Correct Answer: C

Rationale: The correct answer is C because shining a light across the pupil from the side allows for both direct (ipsilateral) and consensual (contralateral) pupillary constriction to be observed. This technique helps to assess the integrity of the cranial nerves involved in the pupillary light reflex (CN II and III). Direct constriction occurs in the eye exposed to the light, while consensual constriction occurs in the opposite eye. This comprehensive assessment ensures that both pupils are responding appropriately to light stimulation, providing a more accurate evaluation of the reflex. Choice A is incorrect because inspecting for pupillary constriction from directly in front may not adequately assess for consensual constriction in the opposite eye. Choice B is incorrect as asking the patient to follow the penlight in eight directions does not specifically target the pupillary light reflex. Choice D is incorrect as it focuses on accommodation rather than the pupillary light reflex.