Hi.. Can understand your concern... As per your complain swelling on hand and rash are due to allergic reaction of the venom left by the sting of the insect leading to inflammation and swelling, increased temperature of the localized inflamed area are signs of inflammation. Rash is also due to allergic reaction. In case if you do not have any systemic symptoms you need not to worry but even a little sign of anaphylaxis should be taken seriously and Emergency room should be consulted.. For localized allergy Antihistamines like Claritin or Benadryl or Allegra should be taken twice daily for 5 days.. For relief from pain OTC painkiller like Ibuprofen can be taken.. Apply ice packs over the inflamed area.. Application of steroid based ointment over the inflamed lesion can help.. Application of numbing gel like Lignocaine gel can be applied for pain relief.. If you see the stinger still present over the skin removal of the stinger shuld be done.. Hope this information helps.. Thanks and regards.. Dr.Honey Nandwani Arora..