Varicella zoster virus meningitis under ustekinumab because of plaque psoriasis.

Ustekinumab, a monoclonal antibody that binds to the shared p40 subunit of interleukin (IL)-12 and IL-23, is approved in the USA and Europe for moderate to severe plaque psoriasis. There are concerns that biologic treatments like ustekinumab may lead to an increased rate of infections. We report a 77-year-old woman who developed varicella zoster virus meningitis 8 weeks after initiation of ustekinumab therapy because of plaque psoriasis. She presented clinically with sudden onset of fatigue, vertigo, nausea and epileptic seizures. Investigations of the cerebrospinal fluid revealed 522/3 cells, lactate 2.9 mmol/L, protein 232 mg/dL and 2.4 × 103 varicella zoster virus. After 3 weeks of therapy with acyclovir she recovered. We conclude that infection by varicella zoster virus has to be considered as a differential diagnosis in patients with newly developing neurological or psychiatric abnormalities under immunosuppressive therapy.