A 22-year-old student comes to the physician complaining of 4 days of fever, double vision, and painful swelling around his eyes. He also has significant muscle pain in his neck and jaw muscles. Two weeks ago, the patient returned from a trip to central Mexico. One week after his return, he developed abdominal pain, nausea, vomiting, and diarrhea. These symptoms resolved spontaneously. He has a history of intravenous drug abuse but recently completed a drug rehabilitation program. His temperature is 38.3 C (101 F), blood pressure is 110/70 mm Hg, pulse is 92/min, and respirations are 14/min. Physical examination shows subungual splinter hemorrhages, periorbital edema, and chemosis. Lungs are clear to auscultation. Cardiac examination shows no murmurs. The abdomen is soft and nontender without organomegaly. Laboratory results are as follows: Which of the following is the most likely diagnosis?

Question

A 22-year-old student comes to the physician complaining of 4 days of fever, double vision, and painful swelling around his eyes.  He also has significant muscle pain in his neck and jaw muscles.  Two weeks ago, the patient returned from a trip to central Mexico.  One week after his return, he developed abdominal pain, nausea, vomiting, and diarrhea.  These symptoms resolved spontaneously.  He has a history of intravenous drug abuse but recently completed a drug rehabilitation program.  His temperature is 38.3 C (101 F), blood pressure is 110/70 mm Hg, pulse is 92/min, and respirations are 14/min.  Physical examination shows subungual splinter hemorrhages, periorbital edema, and chemosis.  Lungs are clear to auscultation.  Cardiac examination shows no murmurs.  The abdomen is soft and nontender without organomegaly.  Laboratory results are as follows:  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d472_25d7_bc81_5bebdde36f4c_MD0003_00 This patient's presentation suggests trichinellosis (also known as trichinosis), a parasitic infection caused by the roundworm Trichinella. The organism is prevalent worldwide, but the infection is more common in Mexico, China, Thailand, parts of central Europe, and Argentina. Infection usually occurs after eating undercooked or raw meat (usually pork) containing encysted Trichinella larvae. Within the first week of ingestion, gastric acid releases the encysted larvae. The larvae invade the small intestine and develop into worms (intestinal stage). Female worms can release new larvae (up to 4 weeks later) that migrate and encyst into striated muscle (muscle stage). During the intestinal stage, patients can be asymptomatic or develop abdominal pain, nausea, vomiting, and diarrhea. During the muscle stage, patients may develop local or systemic findings due to larval migration, including fever, subungual splinter hemorrhages, conjunctival and retinal hemorrhages, periorbital edema, and chemosis. Larvae entering the muscle can cause pain, tenderness, swelling, and weakness (eg, neck, arms, shoulders). Laboratory studies show eosinophilia (usually >20%), the hallmark of the disease. Other findings include possible elevated creatine kinase and leukocytosis. Diagnosis is suspected clinically with the characteristic triad of periorbital edema, myositis, and eosinophilia. Severe disease can involve the heart, lungs, and central nervous system. Mild infections are typically self-limited; severe infections require antiparasitic therapy (eg, mebendazole, albendazole) with corticosteroids. (Choice A) Ascariasis can also present with intestinal symptoms and eosinophilia, but more often has a lung phase with nonproductive cough followed by an asymptomatic intestinal phase. Ascariasis can also present with the worms obstructing the small bowel or bile ducts. This patient's triad of periorbital edema, myositis, and eosinophilia is more consistent with trichinellosis. (Choice B) Dengue fever usually presents with fever, headache, retro-orbital pain, rash, and significant myalgia and arthralgias. Patients can also develop hemorrhagic dengue fever with significant hemorrhage in the skin or nose. However, dengue fever does not usually cause marked eosinophilia. (Choice C) Acute giardiasis can present with diarrhea (can be steatorrhea), flatulence, abdominal cramps, weight loss, and nausea. However, giardia usually does not cause the significant myalgias or eosinophilia seen in this patient. (Choice D) Infective endocarditis can present with fever, cardiac murmur, and embolic phenomenon (eg, subungual splinter hemorrhages). Although this patient's drug abuse history can suggest endocarditis, this disorder usually does not cause significant eosinophilia or periorbital edema. (Choice F) Typhoid fever usually presents in a progressive manner with fever in the 1st week of illness, abdominal pain and salmon-colored rash in the 2nd week, and hepatosplenomegaly with abdominal complications (eg, intestinal bleeding, perforation) during the 3rd week. However, it does not cause significant eosinophilia. Educational objective: Trichinellosis typically presents with gastrointestinal complaints (eg, abdominal pain, nausea, vomiting) followed by the characteristic triad of periorbital edema, myositis, and eosinophilia (hallmark of the disease). Other findings include fever, subungual splinter hemorrhages, and conjunctival or retinal hemorrhages. References: Epidemiology, diagnosis, treatment, and control of trichinellosis. (http://www.ncbi.nlm.nih.gov/pubmed/19136437)

A 22-Year-Old Student Comes to the Physician Complaining of 4