Steve has just seen a 5-year-old girl who wheezes when exposed to cats. The patient's family history is positive for asthma. You think the child most likely has asthma. What have you just accomplished?

Correct Answer: C

Rationale: By connecting the patient's presenting symptoms (wheezing when exposed to cats) and family history of asthma, you have identified asthma as the most likely diagnosis for the 5-year-old girl. This initial conclusion, based on the available information, is known as a working diagnosis. Further evaluation and testing may be required to confirm the diagnosis, but at this stage, you have established a preliminary understanding of the likely condition affecting the patient.

Correct Answer: C

Rationale: The target heart rate during physical activity is typically calculated as a percentage of maximum heart rate, which is estimated using the formula: 220 - age. For a 30-year-old individual, the estimated maximum heart rate would be 190 beats per minute. Exercising at 60-70% of the maximum heart rate is usually recommended for moderate-intensity physical activity. For this individual, the target heart rate zone would be approximately 114-133 beats per minute. Therefore, achieving a heart rate of 120 beats per minute would fall within the target range and indicate an appropriate level of exertion for effective physical activity.

Correct Answer: C

Rationale: In the context of visual acuity, the numbers in the ratio 20/100 represent a comparison between the patient's vision and normal vision. Specifically, a visual acuity of 20/100 means that the patient can see at 20 feet what a person with normal vision can see at 100 feet. This indicates that the patient's vision is reduced, as she needs to be closer to see the same level of detail compared to someone with normal vision.

Correct Answer: D

Rationale: The scenario described with a strong pulse followed by a weak pulse is characteristic of pulsus paradoxus, a finding often associated with cardiac tamponade. Cardiac tamponade is a medical emergency where there is an accumulation of fluid (such as blood) in the pericardial sac that exerts pressure on the heart, limiting its ability to pump effectively. As a result, patients may exhibit this pulsus paradoxus, where the pulse strength varies with respiration. The other conditions listed (emphysema, asthma exacerbation, severe left heart failure) are not typically associated with this specific pulsatile pattern.

Correct Answer: B

Rationale: The description of dark tan patches with a reddish cast that have sharp borders and fine scales, especially more prominent on the upper back, chest, neck, and upper arms, is classic for tinea versicolor. Tinea versicolor is a superficial fungal infection caused by Malassezia species, which commonly affects individuals who sweat more, such as those working outdoors like the construction worker in this case. The rash is often pruritic (itchy) and can vary in color from tan to pink or red. The fine scales on the patches are a result of the accumulation of the yeast in the affected areas.

Correct Answer: C

Rationale: The most likely cause of neck pain in this scenario is a cervical sprain. A cervical sprain is an injury to the ligaments in the neck as a result of sudden force or trauma, such as a motor vehicle collision. The symptoms of a cervical sprain typically include pain, stiffness in the neck, and muscle spasm. The fact that the patient has pain and spasm over the paraspinous muscles on one side of the neck, along with pain during active range of motion, is characteristic of a sprain. It is important to consider this diagnosis in individuals who have recently experienced trauma to the neck region. Treatment for a cervical sprain usually includes pain management, rest, and gentle stretching exercises to help with recovery.

Correct Answer: D

Rationale: The presence of a palpable pulsatile abdominal mass in a patient like Mr. Martin, who is a smoker and at risk for vascular diseases, is concerning for an abdominal aortic aneurysm (AAA). Immediate referral to a vascular surgeon is essential for further evaluation and management. AAA can be a life-threatening condition if left untreated, as it can lead to rupture and severe internal bleeding. Therefore, prompt specialist evaluation and monitoring are crucial in such cases. Waiting for 3 or 6 months for reevaluation could potentially lead to a delayed diagnosis and increase the risk of complications. Abdominal ultrasound is typically the diagnostic test of choice to confirm the presence and size of the aneurysm.

Correct Answer: B

Rationale: Even after a unilateral mastectomy, women should continue to self-examine and have regular clinical examinations for any signs of recurrence or new masses. It is important to closely monitor the surgical scar area for any changes or abnormalities, as breast cancer can still occur in the remaining breast tissue. Regular breast examinations remain important in the early detection of any potential issues, even after mastectomy.

Correct Answer: D

Rationale: The closed fist gesture over the sternum to describe chest pain is a typical characteristic of angina pectoris. Angina pectoris is chest pain or discomfort that occurs when the heart muscle does not receive enough oxygen-rich blood. The gesture of clenching a fist over the sternum is often used to describe the tight, squeezing, or pressure-like discomfort experienced with angina. This type of chest pain is typically triggered by physical or emotional stress and is relieved by rest or medications like nitroglycerin. Considering the patient's age, smoking history, and the description of the chest pain gesture, angina pectoris should be a top consideration in this case.