Dr. Catherine Larned said workers at her Pine Island practice contacted the Lee County Sheriff's Office after discovering an envelope that had an unknown white substance on it, the Fort Myers (Fla.) News-Press reported Wednesday.
Deputies and a local hazardous materials team arrived at the scene and authorities got in contact with the person named on the return address of the envelope.
"The person said they were eating a doughnut when they mailed the envelope and some powdered sugar must have gotten on the envelope," Lee County sheriff's Sgt. Stephanie Eller said.
Eller praised the response of staff at Larned's office.
"With everything going on in the world today, you can't be too careful," Eller said.