Persistent Facial Blanching after Botulinum Toxin Injection.

We report the case of a 38-year-old male patient who presented with blanching of the face after strenuous exercise or physical exertion. The symptoms regressed in a relaxed state. Three years before presentation, he underwent botulinum toxin injections in the affected areas of the face. Facial blanching is a rare side effect of botulinum toxin injection. The postulated pathophysiology involves different transmitters mainly acetylcholine as well as co-transmitters implicated in vasodilation. Usually, facial blanching resolves shortly after waning of the botulinum toxin. However, in our case, the symptoms persisted for a longer time. Till date, therapy options for post-botulinum facial blanching are lacking, mainly due to the temporary aspect of the disease.