Narrow Results

We report a case of phenytoin extravasation complicated by eschar formation. Pre-operative MRI study showed a large non-enhancing area over the dorsum of the imaged right wrist and hand corresponding with the site of phenytoin extravasation and raising the suspicion of subcutaneous tissue necrosis. The MRI findings correlated well with the intra-operative findings. We believe that pre-operative MRI in drug extravasation cases can characterise the type of soft tissue injury and define the extent of injury. This helps the surgeon in the surgical approach and treatment options.

As methylene blue (MB) has been widely used in clinics for in vivo imaging, diagnosis and therapy of various diseases, its biosafety has attracted increasing attention during the past decades, and more and more new findings on the toxicity of MB have been reported in recent years. Although MB exhibits lower toxicity compared to many other reagents for diagnosis and therapy, any potential side effects caused by MB should be clearly known before promoting its clinical use. The side effects of MB are usually dependent on administration dose and route, as well as the reaction with other drugs. Some information on the MB toxicity should be given great attention, as it comes from clinical case reports even based on patient deaths. In this chapter, skin and fat necrosis caused by local injection and intravenous administration of MB, serotonin syndrome caused by the interaction between MB (as a monoamine oxidase inhibitor) and serotonin-reuptake inhibitors described. The contents presented in this chapter may be useful for doctors in approaching the question of how to decrease the clinical medication risk of MB.