Background
Cerebritis is a potentially fatal inflammatory condition typically with presenting symptoms of encephalopathy, seizures, or localizing neurologic deficits. Common culprits of cerebritis include autoimmune conditions as well as infectious causes.
Betadine (or povidone-iodine) is a commonly used antiseptic, made up of a combination of iodine and a water-soluble polymer.1Once applied, the iodine molecule dissociates and penetrates microbial cell membranes, interacts with proteins, nucleotides, and fatty acids within the cell, and ultimately results in rapid cell death.1 This mechanism of action promotes a wide antimicrobial spectrum as well as efficacy in disrupting biofilms.1,2
Betadine may cause irritant dermatitis when applied to the skin. This develops as iodine exerts similar destructive effects to those mentioned previously. The effect of betadine on neural tissue is less understood. In a study evaluating varying concentrations of betadine on rabbit brains, Li et. al. describe histologic evidence of neural tissue damage in the absence of clinical indications of such damage, and tissue damage worsened with increasing concentrations.3 This evidence is further supported by Wang et. al. who noted that lower concentrations of betadine (eg. 0.5%) was beneficial for tissue healing but higher concentrations (eg. 5% or more) had the opposite effect.4 To our knowledge there are no reports of iodine toxicity resulting in sterile cerebritis secondary to recurrent topical betadine application. Here we report an interesting presentation of sterile cerebritis precipitated by chronic topical betadine application during the care of an open scalp wound.