A 35-year-old man comes to the office due to joint pain. The patient is a charter pilot and operates flights from Wisconsin to the Caribbean islands, where he frequently stays for several weeks. During his most recent trip 3 months ago, he had fever and malaise for several days accompanied by severe pain in his fingers, wrists, and ankles. Since then, he has had persistent joint pain that has slightly improved over time. The patient has no fever, night sweats, rash, or abdominal symptoms. He is also an avid hiker. Temperature is 37 C (98.6 F), blood pressure is 130/72 mm Hg, and pulse is 80/min. No scleral icterus, mucosal lesions, or lymphadenopathy is present. The lungs are clear on auscultation, and there are no heart murmurs. The abdomen is soft and nontender with no hepatosplenomegaly. Tenderness and mild swelling are noted in the bilateral wrists, metacarpophalangeal joints, and ankles. No rash is present. Blood cell counts and serum chemistry study results are within normal limits. Which of the following is the most likely cause of this patient's symptoms?

Question

A 35-year-old man comes to the office due to joint pain.  The patient is a charter pilot and operates flights from Wisconsin to the Caribbean islands, where he frequently stays for several weeks.  During his most recent trip 3 months ago, he had fever and malaise for several days accompanied by severe pain in his fingers, wrists, and ankles.  Since then, he has had persistent joint pain that has slightly improved over time.  The patient has no fever, night sweats, rash, or abdominal symptoms.  He is also an avid hiker.  Temperature is 37 C (98.6 F), blood pressure is 130/72 mm Hg, and pulse is 80/min.  No scleral icterus, mucosal lesions, or lymphadenopathy is present.  The lungs are clear on auscultation, and there are no heart murmurs.  The abdomen is soft and nontender with no hepatosplenomegaly.  Tenderness and mild swelling are noted in the bilateral wrists, metacarpophalangeal joints, and ankles.  No rash is present.  Blood cell counts and serum chemistry study results are within normal limits.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

Explanation: 11ec2b69_c0aa_76c2_8f63_d373063aff50_MD0005_00 This patient went to the Caribbean islands and developed a transient febrile illness accompanied by severe, persistent joint pain indicating chikungunya, an alphavirus infection transmitted by Aedes mosquitoes. Outbreaks are common in tropical and subtropical areas (eg, Africa, Asia, Europe, Caribbean region, the Americas) during the rainy seasons, and travelers may return to their home countries with sequelae of infection. Initial manifestations usually include high fever [>39 C (102 F)], diffuse maculopapular rash, and severe polyarthralgia. The joint pains are typically bilateral and symmetric and begin in the distal extremities (eg, hands, wrists, ankles) but may move proximally; the pain is often severe and frequently limits daily activities. Laboratory assessment usually reveals transient lymphopenia and thrombocytopenia. The diagnosis is made by polymerase chain reaction or serology testing. Although most initial manifestations (eg, fever, rash) resolve spontaneously within a few days, up to 70% of patients develop persistent arthralgia or arthritis lasting months or years. Those with long-standing joint symptoms often require treatment with disease-modifying antirheumatic drugs (eg, methotrexate) for adequate pain relief. (Choice B) Ehrlichiosis is a tick-borne bacterial illness that usually causes acute fever and nonspecific symptoms (eg, malaise, headache). Although arthralgia is common, the presence of severe, persistent polyarticular joint pain indicates a different diagnosis. (Choice C) Lyme disease is a tick-borne bacterial illness that usually causes erythema migrans (a spreading, annular rash) and systemic symptoms in early infection. Monoarthritis of a large joint (eg, knee) may occur in late infection; however, severe polyarticular joint pain in the distal small joints is not consistent with Lyme disease. (Choice D) Malaria is a mosquito-borne protozoal illness that causes fever and flu-like symptoms (eg, shaking chills, headache, myalgia, malaise). Laboratory abnormalities such as anemia and hyperbilirubinemia are common due to red blood cell lysis. Severe, persistent polyarthritis would be atypical. (Choice E) Typhoid fever is a bacterial illness caused by Salmonella infection. Manifestations progress slowly and begin with a week of fever (often with temperature-pulse dissociation) followed by abdominal pain and cutaneous "rose spots." By week 3, hepatosplenomegaly, intestinal bleeding, and intestinal perforation often occur. Educational objective: Chikungunya is a mosquito-borne virus that causes high fever and severe polyarthralgia. The arthralgia is typically bilateral and symmetric and affects distal joints (eg, hands, wrists, ankles). Most symptoms resolve spontaneously, but up to 70% of infected patients develop chronic arthralgia or arthritis. References: Emerging vector-borne diseases. (http://www.ncbi.nlm.nih.gov/pubmed/27929218) Dengue, Zika and chikungunya: emerging arboviruses in the new world. (http://www.ncbi.nlm.nih.gov/pubmed/27833670)

A 35-Year-Old Man Comes to the Office Due to Joint