Pruritic Rash in a Recent Traveler to Central America.

In December 2014, an 18-year-old male presented to Harbor-UCLA Medical Center in Los Angeles, CA with a 3-day history of pruritic, maculopapular rash, which began on the wrists and arms and rapidly spread to the rest of his body, including his palms. Four days before the rash was noted, he had a temperature of 101°F, malaise, myalgia, and polyarthralgia. The arthralgia started in his right wrist, which was swollen but not red. The pain subsequently spread to his other wrist, fingers, and knees in a migratory pattern. He also noted a mild cough, but no congestion, sore throat, conjunctivitis, vomiting, or diarrhea. He reported intermittent generalized headaches, but he denied confusion, irritability, weakness, or abnormal movements. Over the past week of symptoms, his joint pain and headache had subsided substantially, but the itchy rash persisted. The patient’s symptoms began 2 days after he had returned from an 8-day visit to El Salvador. In El Salvador, he stayed in a rural area of the city of Santa Ana in the northwestern part of the country. While there, he swam in a nearby river and hiked, sustaining many mosquito bites on his legs without other known insect or tick bites. He did not have direct contact with animals, but there was a barn with cows across from his house. He denied consuming unpasteurized dairy products and undercooked meats. He did not receive any travel-specific vaccinations or take malaria prophylaxis. None of his family members in El Salvador were ill. The patient otherwise had no past medical history. He was born in Los Angeles and lived there all his life. His only other travel was to El Salvador 4 years ago. He had had 4 lifetime sex partners (all female) with inconsistent condom use. His routine immunizations were appropriate for age. Physical examination revealed a well appearing and cooperative young man with vital signs as listed: temperature 36.9°C, heart rate 89 beats/minute, respiratory rate 16 breaths/minute, and blood pressure 121/79 mm Hg. A diffuse, blanching, morbilliform rash was present on his chest, abdomen, and back, most prominently seen on his upper and lower extremities, excluding the palms and soles (Figure 1). There were few petechiae on his soft palate and right shoulder. He had mild, generalized swelling of his face and lips. He had a single 1 x 1 centimeter, rubbery, tender lymph node in each inguinal region bilaterally. There was no edema, erythema, or tenderness of his joints, and he had full active and passive range of motion. The rest of his examination was unremarkable. Initial laboratory results were as follows: total white blood cell count 5200/mm, with a differential of 68% neutrophils, 14% lymphocytes, 10%monocytes, and 7%eosinophils; hemoglobin 16.1 g/dL; hematocrit 46.9%; platelet count 138 000/mm; and serum electrolytes, hepatic transaminases, and coagulation studies all within normal limits. The urinalysis was normal, and a rapid human immunodeficiency virus serologic test was negative. The Pediatric Infectious Diseases Consultants who saw this patient were asked the following questions: