In the article by Tan et al.3 (Tan T, Tee JW, Han TF: Cell-mediated allergy to cerebral aneurysm clip causing extensive cerebral edema. J Neurosurg 292 J Neurosurg? Volume 123 • July 2015
Neurosurgical forum 121:924–928, October 2014), the authors highlight the first case of vasogenic cerebral edema caused by a cellmediated hypersensitivity reaction 4 years after aneurysm clipping in a 60-year-old woman with a history of severe nickel contact dermatitis.
They discuss the possibility of nickel hypersensitivity, speculating that the intermittent nature of their patient’s cerebral edema may have resulted from the sporadic leaching of nickel from the Phynox clip.
This then produced the cycle of acute-on-chronic cellmediated hypersensitivity response that was visualized on imaging studies.
In contrast with their findings of an acute-chronic cycle of hypersensitivity reaction in a patient with a known nickel allergy, we recently reported on an acute case in a 33-year-old woman who developed a life-threatening allergic vasculitis following clipping of her brain aneurysm several weeks earlier with a nickel-containing clip.1 Our patient progressively declined, facing deteriorating clinical status (i.e., seizures) and additional infarctions.
Repeatedly, neither she nor her family affirmed any contact dermatitis or nickel allergy. Finally, during decompressive surgery, biopsy findings raised the possibility of lymphocytic vasculitis, the nickel allergy was confirmed, and the clip was replaced with a titanium one.
Like the one reported by Tan et al., our case reminds the neurosurgical community of the possibility of nickel sensitivity—acute or chronic.
When possible, screening can be used. Given the 10%–15% rates of nickel allergy, which are higher in women, we also advocate for the routine use of medical-grade titanium clips for aneurysm clipping. We agree with the authors that follow-up cerebral MRI can detect development of cerebral edema,
but we wouldn’t advocate for its routine use in asymptomatic patients given the rarity of this reaction after aneurysm clipping. We reported the findings of this case in our Mayfield Clinic blog.2 The blog addresses the public health issue of nickel allergy, reminding our patients and community to keep their
medical histories up to date with a family member, and we note that even a small detail, such as allergic reaction to jewelry, could become vitally important.
Ryan D. Tackla, MD1,2 Andrew J. Ringer, MD1–3 1 University of Cincinnati (UC) College of Medicine, Cincinnati, OH 2 Comprehensive Stroke Center at UC Neuroscience Institute, Cincinnati, OH 3 Mayfield Clinic, Cincinnati, OH Disclosure? The authors report no conflict of interest.
1. Grande A, Grewal S, Tackla R, Ringer AJ: Life-threatening allergic vasculitis after clipping an unruptured aneurysm: Case report, weighing the risk of nickel allergy. Surg Neurol Int 5 (Suppl 4):S161–S164, 2014
2. Kemper M: Allergic to nickel? Be sure to let your doctor know! (http://www.mayfieldclinicblog.com/allergic-to-nickel-be-sure-to-let-your-doctor-know/) [Accessed April 8, 2015] 3. Tan T, Tee JW, Han TF: Cell-mediated allergy to cerebral aneurysm clip causing extensive cerebral edema. J Neurosurg 121:924–928, 2014