Patients with cancer often require chemotherapeutic and/or radiation treatment. These patients, as well as those with chronic steroid use, immunomodulation therapy use for inflammatory disorders, and inborn or acquired immunodeficiencies are at higher risk of infection. Laboratory values suggestive of an immunosuppressed state include leukopenia and pancytopenia. Steroids can potentiate immunosuppression, even if relatively small amounts are injected into the epidural space. Systemic effects of corticosteroids may increase risk of infection or viral reactivation.
The risks of rare but serious infections must be weighed with the expected benefits of pain relief and functional improvement from epidural steroid injections. Case reports have emerged documenting infectious complications following epidural steroid injections. The root cause of a series of fungal infections following epidural steroid injection was traced to contaminated vial batches of methylprednisolone in the 2010’s [1]. Specific reports have been described for herpes zoster. One report describes herpes esophagitis following a cervical epidural steroid injection [2]. Another case describes cutaneous herpes zoster eruption following serial lumbar epidural steroid injections [3]. Finally numerous case reports describe epidural abscess formation even in the absence of known immunodeficiency [4]. As such, providers should seriously consider the higher risk of infection in the immunosuppressed patient population. Currently, antibiotic prophylaxis is not recommended for epidural steroid injections.
In addition to risks of infection, there are risks of cortisol excess when patients are taking other medications. Several cases describing iatrogenic Cushing’s syndrome, characterized by glucose intolerance, diffuse adipose deposition, and immune dysregulation, highlight the interaction between corticosteroids and ritonavir, a protease inhibitor used to treat Human Immunodeficiency Virus (HIV) [5, 6]. Cushing’s syndrome is the clinical manifestation of cortisol excess from endogenous or exogenous causes. Downstream complications of Cushing’s syndrome are serious: they range from myocardial infarction and stroke to bone loss, hypertension, type 2 diabetes, and depression. Thus, pain providers should perform a review of patient medications with particular attention to the coadministration of ritonavir in HIV-affected patients.
Pain physicians and anesthesia providers should be aware of the risks of epidural steroid injections when counseling patients. While epidural abscess formation is an appropriately often-cited complication, other effects related to administration of steroids should be discussed, including iatrogenic Cushing’s syndrome and immunosuppression.
References:
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Moudgal V, et al. Spinal and paraspinal fungal infections associated with contaminated methylprednisolone injections. Open Forum Infect Dis. 2014 May 14;1(1)
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Davis K, et al. A difficult case to swallow: herpes esophagitis after epidural steroid injection. Am J Ther. 2014;21(1):e9-14.
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Parsons SJ, Hawboldt GS. Herpes zoster: a previously unrecognized complication of epidural steroids in the treatment of complex regional pain syndrome. J Pain Symptom Manage. 2003;25(3):198-9.
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Kraeutler MJ, et al. Spinal subdural abscess following epidural steroid injection. J Neurosurg Spine. 2015; 22(1):90-3.
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Maviki M, et al. Injecting epidural and intra-articular triamcinolone in HIV-positive patients on ritonavir: beware of iatrogenic Cushing’s syndrome. Skeletal Radiol. 2013; 42(2):313-5.
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Albert NE, et al. Ritonavir and epidural triamcinolone as a cause of iatrogenic Cushing’s syndrome. Am J Med Sci. 2012;344(1):72-4.
