A patient presents with well-demarcated, hypopigmented macules with fine scaling, affecting the trunk and proximal extremities. The patient reports a history of sun exposure and outdoor activities. Which of the following conditions is most likely responsible for this presentation?

Correct Answer: A

Rationale: The presentation of well-demarcated, hypopigmented macules with fine scaling on the trunk and proximal extremities is classic for tinea versicolor. Tinea versicolor is a common superficial fungal infection caused by Malassezia spp., which leads to hypo- or hyperpigmented patches on the skin. The condition often occurs in individuals with increased sebum production due to factors such as hot and humid climates, sweating, and oily skin. History of sun exposure and outdoor activities is also commonly reported by patients with tinea versicolor. Treatment usually involves antifungal medications applied topically or taken orally to eliminate the fungus. Differentiating tinea versicolor from other skin conditions, such as vitiligo, pityriasis rosea, or seborrheic keratosis, is important for appropriate management.

Correct Answer: A

Rationale: Zenker's diverticulum is a condition in which there is a pouch or sac that forms at the posterior pharyngeal wall above the upper esophageal sphincter. It can present with symptoms such as sensation of a foreign body stuck in the throat, difficulty swallowing (dysphagia), and odynophagia (painful swallowing). Flexible laryngoscopy can reveal a submucosal mass arising from the posterior pharyngeal wall, which is characteristic of Zenker's diverticulum.

Correct Answer: A

Rationale: The presentation described with sudden-onset, painless vision loss, a cherry-red spot at the macula, and attenuated retinal vessels is classic for central retinal artery occlusion (CRAO). CRAO occurs when the central retinal artery, which supplies blood to the inner retinal layers, becomes occluded. The cherry-red spot is due to the exposure of the underlying choroid, which still appears red as it is not affected by the blockage. Attenuated retinal vessels and a pale retina may also be seen due to ischemia. In contrast, central retinal vein occlusion (choice B) presents with sudden painless vision loss, retinal hemorrhages, dilated retinal veins, and cotton-wool spots. Retinal detachment (choice C) typically presents with flashes, floaters, and a curtain-like shadow across the vision. Acute angle-closure glaucoma (

Correct Answer: A

Rationale: The presentation of sudden-onset, painless vision loss in the right eye with a cherry-red spot at the macula and attenuated retinal vessels is classic for central retinal artery occlusion (CRAO). In this condition, the blockage of the central retinal artery results in severe ischemia of the retina, leading to rapid and profound vision loss. The cherry-red spot at the macula is a result of preserved choroidal circulation contrasting with the pale, ischemic retina. Attenuated retinal vessels are also commonly observed due to decreased blood flow. Prompt evaluation and management are critical in CRAO to potentially restore some vision and prevent further ischemic damage to the retina.

Correct Answer: A

Rationale: The described presentation is classic for acute angle-closure glaucoma. This condition is characterized by sudden-onset severe eye pain, headache, nausea, and vomiting. The red eye, steamy cornea (corneal edema), and mid-dilated non-reactive pupil are consistent with acute angle-closure glaucoma. The sudden increase in intraocular pressure leads to impaired aqueous humor outflow, causing these symptoms. Immediate intervention is required to prevent permanent vision loss in such cases. Central retinal artery occlusion would present with sudden painless vision loss. Optic neuritis typically presents with vision loss and pain with eye movements. Corneal ulcer presents with eye discomfort, foreign body sensation, and may have a history of corneal trauma or contact lens wear.