A few days after a summer hiking trip, a 25-year-old man comes to the clinic with a rash. On examination, the nurse notes that the rash is red and circular with central clearing, and is located across his midriff and behind his knees. The nurse suspects:

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: damage to the trigeminal nerve. Trigeminal nerve damage can result in the inability to differentiate between sharp and dull sensations on the face. The trigeminal nerve is responsible for transmitting sensory information from the face to the brain. Bell's palsy (choice A) affects facial muscles, not sensory perception. Frostbite (choice C) typically causes numbness rather than loss of sensation discrimination. Scleroderma (choice D) is a connective tissue disorder that does not directly affect sensory perception on the face.

Correct Answer: A

Rationale: The correct answer is A: thyroid gland. Thyroxine is a hormone produced by the thyroid gland. An elevated thyroxine level indicates a potential thyroid gland dysfunction. The nurse would examine the thyroid gland to assess its size, texture, and any signs of abnormalities. Incorrect choices: B: Parotid gland - This gland is responsible for producing saliva, not thyroxine. C: Adrenal gland - Responsible for producing hormones like cortisol and adrenaline, not thyroxine. D: Thyroxine gland - There is no such thing as a "thyroxine gland." Thyroxine is a hormone produced by the thyroid gland.

Correct Answer: A

Rationale: The correct answer is A: At birth, the head is one fifth the total length. This is because newborns have relatively larger heads compared to their body size. This is known as cephalocaudal growth, where development starts from the head and progresses down the body. The head being one-fifth of the total length is a normal proportion in newborns. Choice B is incorrect because at birth, the chest circumference is usually greater than the head circumference. Choice C is incorrect as the head size reaches about 80% of its final size by age 2, not 3 years old. Choice D is incorrect because the closure of the anterior fontanelle at 2 months does not necessarily mean the head will appear proportionate to the body; it continues to grow in proportion to the body size.

Correct Answer: D

Rationale: The signs and symptoms - severe headache, high fever, and neck stiffness - in a young adult point towards meningeal inflammation. The combination of these symptoms is indicative of a potential infection or inflammation of the meninges, the protective membranes surrounding the brain and spinal cord. The presence of fever and neck stiffness, in addition to the severe headache, raises concern for meningitis, an infection of the meninges. This is a medical emergency that requires prompt evaluation and treatment. Other choices are incorrect because: A: Head injury usually presents with a history of trauma, which is not mentioned in the scenario. B: Cluster headaches typically do not present with fever and neck stiffness. C: Migraine headaches do not typically cause such high fever and neck stiffness.