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.