Which of the following is a common clinical manifestation of osteoarthritis in the hip joint?

Correct Answer: C

Rationale: Osteoarthritis in the hip joint can lead to weakness or dysfunction in the hip abductor muscles, causing a Trendelenburg gait. This gait abnormality is characterized by a dropping of the pelvis on the opposite side of the affected hip during weight-bearing on the affected leg. It is a common clinical manifestation of hip osteoarthritis due to the muscle weakness and altered mechanics in the hip joint. Baker's cyst is associated with knee osteoarthritis, Heberden's nodes are commonly seen in osteoarthritis of the fingers, and Swan-neck deformity is typically seen in rheumatoid arthritis, not osteoarthritis.

Correct Answer: B

Rationale: The patient's presentation with sudden-onset severe lower abdominal pain, nausea, vomiting, inability to pass urine, suprapubic tenderness, and a palpable bladder is classic for acute urinary retention. Acute urinary retention is a urological emergency characterized by the sudden inability to pass urine due to the inability to empty the bladder completely. The palpable bladder on physical examination indicates significant bladder distension. This condition can be caused by multiple factors such as bladder outlet obstruction, neurogenic causes, or medications affecting bladder function. Prompt intervention is necessary to relieve the bladder distension, alleviate symptoms, and prevent complications like bladder rupture.

Correct Answer: B

Rationale: Oxybutynin is a medication commonly used for the management of overactive bladder (OAB) symptoms such as urinary urgency and frequency. It belongs to a class of medications known as anticholinergics, which work by relaxing the bladder muscles and reducing bladder spasms. By doing so, it helps to decrease the symptoms of OAB, including frequent urination, sudden urges to urinate, and leakage. Oxybutynin can be taken orally in tablet form, as a transdermal patch, or as a gel, providing various options for patients based on their preferences and needs. Overall, oxybutynin is an effective treatment option for individuals experiencing overactive bladder symptoms.

Correct Answer: C

Rationale: The clinical presentation of fever, malaise, maculopapular rash starting on the face and spreading to the trunk and extremities, along with leukopenia and thrombocytopenia, is highly suggestive of Rocky Mountain spotted fever (RMSF) caused by Rickettsia rickettsii. RMSF is a tick-borne illness transmitted by the American dog tick, Rocky Mountain wood tick, and brown dog tick. The constellation of symptoms described aligns well with the typical presentation of RMSF. Borrelia burgdorferi causes Lyme disease, which presents with erythema migrans but does not typically cause leukopenia or thrombocytopenia. Plasmodium falciparum is the causative agent of severe malaria and would present with symptoms such as cyclic fevers, anemia, and jaundice but not the described rash distribution.

Correct Answer: A

Rationale: The most likely causative agent in this scenario is Plasmodium falciparum, a protozoan parasite that causes malaria. The patient's symptoms of fever, chills, headache, and myalgia align with the typical presentation of malaria. Additionally, the presence of intraerythrocytic ring forms and trophozoites on blood smear examination is characteristic of Plasmodium species, particularly P. falciparum, which causes the most severe form of malaria.