A returning traveller with fever, facial swelling, and skin lesions

A 58 year old man presented to the emergency department with fevers and lethargy. He had recently been in Zambia for 15 days, where he had spent time in Lusaka and at a game reserve. Three days earlier, while still in Lusaka, he had noted painful swellings on his right leg and fever, and although a malaria test was negative the fevers continued, so he returned home to Germany early. At presentation, he was drowsy and his speech was slurred, so the history was obtained from his sister. He had not taken antimalarials during his trip, but he had been vaccinated against tetanus, diphtheria, and rabies before travel.

On examination his temperature was 39.4°C, respiration 18 breaths/min, pulse 96 beats/min, and blood pressure 95/80 mm Hg. His Glasgow coma score was 12/15, and facial swelling was noted around his eyes and cheeks. Apart from moderate hepatosplenomegaly and a systolic mitral valve click owing to a St Jude prosthesis implanted five years earlier, his physical examination was normal. There was no focal neurological abnormality or evidence of meningism. A generalised macular exanthema was noted on his trunk, along with two indurated skin lesions about 6 cm in diameter on his right leg (fig 1⇓).

Blood tests showed haemoglobin 126 g/L (normal range 140-180), leucocytes 5.6×10⁹ cells/L (4-11; lymphocytes 0.02 (0.25-0.4.), neutrophils 0.84 (0.50-0.75)), platelets 40×10⁹ cells/L (150-400), C reactive protein 1807 μmol/L (8-31), creatine kinase 364 U/L (<171), total bilirubin 51.85 μmol/L (<17.0), aspartate aminotransferase 163 U/L (<35), alanine aminotransferase 205 U/L (<45), γ-glutamyltransferase 274 (<55) U/L, serum creatinine 477.36 μmol/L (<97). Serum electrolytes were within the normal range. Urine dipstick was positive for protein, erythrocytes, and leucocytes as well as some hyaline casts. Blood films were negative for malaria but showed unusual extracellular structures (fig 2 …