What Causes Rash Around The Contraceptive Implant?

my daughter has had the contraceptive implant in her arm about 10 days ago. 2 months ago she was poorly and diagnosed with erthima multiforme which has since cleared. However tonight she has developed a rash around her implant site and is spreading up her arm which looks simular to the rash she had previously could the implant have caused the erthima multiforme to return?