<s>[INST] Seven days ago, a rash started in the middle of my back and on my left butt cheek.  At first it looked like a couple of mosquitoe bites but then they got bigger, whelped up and spread.  Still within a 2 inch region though.  The one on my buttox has a red line now coming down from it.  I now have 4 more on my left side and one on my stomach. One of the spots on my side has a red line.   They do not hurt but they itch and are not getting better.  The one on my buttox is getting crusty.  Any ideas what this could be? [/INST] I think u are suffering from tinea corporis with secondary bacterial infection.it is due to excessive moisteriser over the buttocks.It can be treated with antihistamine atarax 25 mg .antibiotic.to relieve from crusting .then use oral and topical terbinafine for fourteen days </s>