A 26-year-old woman comes to the emergency department with a 1-day history of chills, headache, and muscle aches. A week ago, she returned from a month-long trip to Tanzania. During her travels, she stayed with friends in local hotels and ate mostly at local restaurants. She spent significant time outdoors, including swimming in local lakes. She had taken atovaquone-proguanil for malaria prophylaxis and was compliant with therapy.
The patient's temperature is 38 C (100.4 F). Physical examination shows multiple urticaria-type lesions on the trunk and upper extremities.
Laboratory studies are as follows:

Which of the following is the most likely diagnosis?

Question

A 26-year-old woman comes to the emergency department with a 1-day history of chills, headache, and muscle aches.  A week ago, she returned from a month-long trip to Tanzania.  During her travels, she stayed with friends in local hotels and ate mostly at local restaurants.  She spent significant time outdoors, including swimming in local lakes.  She had taken atovaquone-proguanil for malaria prophylaxis and was compliant with therapy.
The patient's temperature is 38 C (100.4 F).  Physical examination shows multiple urticaria-type lesions on the trunk and upper extremities.
Laboratory studies are as follows:

Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Acute onset of fevers, allergic-type symptoms (urticarial lesions, angioedema), and robust eosinophilia in the setting of a recent trip to sub-Saharan Africa with freshwater exposure is suggestive of acute schistosomiasis syndrome (Katayama fever). This is a systemic hypersensitivity reaction against schistosomal eggs and larvae, typically occurring 14-28 days after infection. Chest x-ray infiltrates may be present. Microscopic examination for schistosomiasis eggs and serologic testing may be negative in acute schistosomiasis. The episode is usually self-limiting (days to weeks), and management is with corticosteroids during the acute phase followed by antihelminthic therapy (eg, praziquantel) to prevent long-term sequelae of helminth infection (eg, hydronephrosis, bladder squamous cell carcinoma). (Choice A) Amebiasis typically manifests with nonspecific or gastrointestinal symptoms (flatulence, diarrhea, lactose intolerance, malabsorption). Fever would be rare. (Choice B) Unremitting high fevers and severe polyarthralgia would be more characteristic of Chikungunya fever. (Choice C) Cutaneous leishmaniasis is due to a protozoan parasite transmitted to humans via sandfly bites. It usually presents as a nonpruritic red papule that forms an ulcer with granulomatous tissue at the base and raised margins. Cutaneous leishmaniasis (Choice D) Malaria is not classically associated with urticarial lesions or eosinophilia. This patient's normal hemoglobin and platelet counts and her compliance with prophylaxis make malaria a less likely diagnosis. Educational objective: Consider acute schistosomiasis (Katayama fever) among patients presenting with fever and eosinophilia after return from an endemic area, including sub-Saharan Africa. Corticosteroids and supportive care are indicated in the acute setting followed by antiparasitic treatment after acute symptoms resolve. __________ References: Katayama syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/17317603)

A 26-Year-Old Woman Comes to the Emergency Department with a 1-Day