Correct Answer: B

Rationale: The correct answer is B: know that these are scars caused from frequent ear infections. The presence of dense white patches on the tympanic membrane in a patient with a history of chronic ear infections indicates scarring from previous infections. This is a common finding in individuals who have experienced recurrent middle ear infections. The other choices are incorrect because: A) Fungal infections typically present with different characteristics such as discoloration or debris in the ear canal, not dense white patches on the tympanic membrane. C) Blood in the middle ear would manifest as redness or hemorrhage, not white patches. D) While scarring may affect hearing, the description of the tympanic membrane in this case does not suggest any immediate concern for hearing loss.

Correct Answer: B

Rationale: The correct answer is B: Lyme disease. The presentation of a red circular rash with central clearing, known as erythema migrans, following a hiking trip in the summer is highly indicative of Lyme disease. The specific distribution of the rash across the midriff and behind the knees aligns with typical areas where the rash appears in Lyme disease cases. This rash is a hallmark sign of early Lyme disease caused by the bacterium Borrelia burgdorferi transmitted through the bite of an infected tick. Other answer choices are incorrect because rubeola presents with a different rash pattern, an allergy to mosquito bites would not typically present in this manner, and Rocky Mountain spotted fever typically presents with a different rash appearance and distribution.

Correct Answer: B

Rationale: The correct answer is B: A dark retinal background. This is because individuals of African descent typically have a higher concentration of melanin in their eyes, resulting in a darker retinal background. This can affect the appearance of the fundus during eye examinations. Incorrect choices: A: Increased night vision - Night vision is not directly influenced by melanin levels in the eyes and is more related to the function of rods and cones in the retina. C: Increased photosensitivity - Melanin provides some protection against UV light, so individuals with darker retinas may have lower photosensitivity. D: Narrowed palpebral fissures - Palpebral fissures refer to the opening between the eyelids and are not typically influenced by melanin levels in the eyes.

Correct Answer: B

Rationale: The correct answer is B because the patient's symptoms (change in mole size, color changes, itching, burning, bleeding) are concerning for melanoma, a type of skin cancer. Given her history of blistering sunburns, early evaluation and referral are crucial for timely intervention. Option A is incorrect as it delays necessary evaluation. Option C is irrelevant as the symptoms suggest a serious condition, not environmental irritants. Option D is incorrect as compound nevi typically do not present with the described symptoms and are not common in this age group.

Correct Answer: B

Rationale: The correct answer is B: acute otitis media. In this case, the presentation of a bright red tympanic membrane and absence of the light reflex are indicative of inflammation and fluid accumulation in the middle ear, which are classic signs of acute otitis media. This condition commonly occurs in young children, especially after a recent upper respiratory infection. Incorrect choices: A: Fungal infection is less likely in this case as the symptoms are more consistent with acute bacterial infection seen in otitis media. C: Rupture of the drum would typically present with sudden relief of pain and discharge from the ear, which is not described in the scenario. D: Blood behind the drum (hemotympanum) is uncommon in children with acute otitis media and would usually be associated with trauma or barotrauma.