Cerebrospinal fluid eosinophilia associated with intraventricular shunts.

CSF eosinophilia (CSF-eo) is uncommon and is usually caused by helminthic infections. However, it has also been found in ∼30% of patients experiencing intraventricular shunt malfunctions. We present a case report and review the conditions associated with CSF-eo and their prophylaxis. An 8 year-old boy with tetraventricular hydrocephalus has had several shunt malfunctions over the last three years. During hospitalization in January 2009 for shunt revision, a transient 30% eosinophilia was detected in his cerebral spinal fluid (CSF) concomitant with Staphylococcus epidermidis infection and long term vancomycin administration. After several shunt replacements and antibiotic treatment, CSF-eo eventually disappeared with good overall clinical response. CSF-eo is a transient and focal event mainly associated with infection, reactions to foreign substances, particles or blood, or obstruction of tubing by normal or fibro-granulomatous tissues. Infection associated with CSF-eo is usually caused by S. epidermidis and Propioniumbacterium acnes. In addition to infection, allergy to silicone and other foreign materials may also be a cause of CSF-eo. We review the diversity of conditions and proposed mechanisms associated with CSF-eo, as well as recommendations for the care of patients with shunts. Detection of CSF-eo has been shown to be a useful indicator of shunt malfunction. As such, it provides physicians with an indicator of a hypersensitivity reaction that is underway or the need to identify bacterial infection. We also highlight the need for improved biocompatibility of shunt hardware and describe strategies to avoid conditions leading to shunt malfunction.