How To Treat Raised Area With Red Spots On Left Leg?

i have a raised area on the upper outside area of my left leg, noticed it two days ago, my skin hurts in a larger area around it , hurts just to slightly run my fingers over, now today about twelve inches down from the raised area i developed a red spot with what appears to hav several tiny white dots, i noticed around the syatic area just a while ago, something with a little irritating , i looked and there was another of the red spots, it was as though i could feel it developing. as for when i had first noticed the lump my leg seemed painful even some what to walk, (pain in the area along with pain around to my syatic area) there is no itching , I dont recall hurting it. I looked up several different bite markings havent found anything, can you give me some insite. Thank You , Cindy