<s>[INST] Painful skin rash on the arm. Could it be a spider bite?I have what I think is a spider bite on my thigh. It s a red ring, about 1.5 inches in diameter. It s raised and hard in the center with what looks like a white speck right in the middle. It s been there a couple of days and is painful to the touch and just a little sore. What do you think it may be? [/INST] Hello. Thanks for writing to us at healthcaremagicSeems like it is bacterial infection of the skin, since it is sore and probably has a central pus point. Spider bites are different, burning is a prominent feature in spider bite, and they usually do have some itching, as well.If you were one of my patients I would have treated you empirically with an oral antibiotic; one from penicillin group of drugs (cloxacillin or flucloxacillin). That would be good enough. It is a prescription drug, therefore, you must ask for a prescription of these from your physician.Topically you may use an OTC topical antibacterial e.g 2% mupirocin cream, twice daily.An OTC pain killer would provide you symptomatic relief from pain and swelling.Regards </s>