CASE REPORT Clinical peritonitis from allergy to silicone ventriculoperitoneal shunt Michael Kurin 1 • Kenneth Lee 2 • Paul Gardner 3 • Merritt Fajt 4 • Chandraprakash Umapathy 1 • Kenneth Fasanella 5 Received: 18 January 2017 / Accepted: 23 February 2017 Ó Japanese Society of Gastroenterology 2017 Abstract Silicones are inorganic compounds that have been used for the purpose of shunting ventricular fluid since the mid-20th century [1]. Complications of ven- triculoperitoneal shunts have rarely been attributed to sil- icone allergy, with only a handful of cases reported in literature. The classic presentation of allergy to silicone ventriculoperitoneal shunt, i.e., abdominal pain with recurrent skin breakdown along the shunt tract, is non- specific and difficult to distinguish clinically from other causes of shunt-related symptoms. It can be diagnosed by detection of antisilicone antibodies and is treated with removal of the shunt and replacement, if needed, with a polyurethane shunt system. We report the first case of suspected silicone allergy presenting as clinical peritonitis without overt colonic perforation. Keywords Peritonitis Á Silicone Á Allergy Á Ventriculoperitoneal shunt Introduction Abdominal pain in patients with ventriculoperitoneal (VP) shunt can be difficult to evaluate, and is sometimes related to shunt malfunction or infection. Allergic reaction to sil- icone is a very rare complication of VP shunt placement that can cause abdominal pain and local skin breakdown. Silicone allergy may be underdiagnosed and should be considered in patients with VP shunt and persistent abdominal pain after infection has been ruled out. We present a case of suspected silicone allergy as the etiology of persistent abdominal pain with peritoneal signs. The case A 62-year-old woman with history of pseudotumor cerebri and placement of a silicone-based VP shunt 5 years ago presented with headaches and abdominal pain. Previously, she had required two revisions for distal shunt malfunction presenting as headaches and visual field defects, most recently 10 months prior to presentation. Nine days prior to presentation, the patient was admitted with headaches, severe neck pain along the shunt tract, and abdominal pain but no papilledema. Cerebrospinal fluid (CSF) studies were notable for 21 white blood cells (WBCs) per cubic milimeter (cu mm) and protein of 90 mg/dL with negative infectious workup and normal opening pressure. Head computed tomography (CT) was unremarkable, and nuclear shuntogram demonstrated delayed distal flow but patency. She was discharged home without symptom res- olution. Shortly thereafter, she presented again with worsening headaches, altered mental status, right ptosis, and diffuse abdominal pain worst in the left lower quad- rant. Her pain was precipitated by defecation and urination, Article Guarantor: K. Fasanella. & Michael Kurin kurinm@upmc.edu 1 Department of General Internal Medicine, University of Pittsburgh Medical Center, 200 Lothrop St., Room N 715, Pittsburgh, PA 15213, USA 2 Division of Gastrointestinal Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA 3 Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, PA, USA 4 Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA 5 Division of Gastroenterology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA 123 Clin J Gastroenterol DOI 10.1007/s12328-017-0729-0