Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns... As per your complain purple skin at the site of bee sting seems to be due to formation of a bruise that can be due to perforation of a small blood vessel with the bee stinger leading to spillage of blood into the soft tissues and forming a bruise that is appearing as a purple discolouration.. You need not to worry as although it can take a few day to almost a month to fade off but will gradually fade away.. You can apply Heparin gel as it will help in faster fading of the bruises.. You can do alternate warm and cool compresses.. In case if there is no improvement in a month or if the symptoms worsen consult a General Physician and get evaluated.. Hope this information helps.. Thanks and regards.. Dr. Honey Nandwani Arora..