Could My Red, Itchy, And Darkening Facial Rash Three Weeks After Thermage Be A Reaction To The Treatment Or A Food Allergy?

3 weeks after I had thermage treatment, I had red rashes in my face particularly on both sides of cheeks and above my mouth and it turned black . My face also is itchy I had flare ups of red rash. Is this related to my thermage treatment or allergy with food?