MRCP2-0901

MRCP2-0901

A 35 year old male of Arabic descent with bullous pemphigus is admitted for intravenous immunoglobulins. He has no significant medical history, has not traveled recently, and has lived in rural Norfolk his entire life. On the fourth day of treatment, he experiences fever, nausea, and vomiting. Upon examination, mild neck stiffness and photophobia are noted, and he complains of a headache in the back of his head. The following serum markers are present:

– WBC: 14.5 * 109/l
– Neuts: 11.2 * 109/l
– Na+: 134 mmol/l
– K+: 3.9 mmol/l
– Urea: 4.8 mmol/l
– Creatinine: 82 µmol/l
– CRP: 5 mg/l

A CT scan of the head shows no abnormalities. The immunoglobulin treatment is discontinued, and a lumbar puncture is performed. The results show a white blood cell count of 10/mm3, protein of 0.4g/L, no organisms, and an opening pressure of 17.8 cm H2O. Blood cultures taken during a fever spike do not show any organisms after 48 hours. What is the diagnosis?