Figure 2 Percentage of positive varicella‐zoster virus (VZV) polymerase chain reaction (PCR) and anti‐VZV antibodies (anti‐VZV‐Ab) in the group of patients with dermatomal rash, in relation to the timing of the lumbar puncture (LP). Samples (n = 13) collected within the first 7 days were never positive for anti‐VZV‐Ab, but 8 (61%) were PCR positive. By contrast, 10 of the 12 (83%) samples collected after 1 week contained oligoclonal anti‐VZV‐Ab, of which only 3 (25%) were still PCR positive.