Why Is The Bite On The Nose Is Continuing To Swell And Looks Like A Scab ?

My husband was bitten or stung by something a week ago. The bite is on his forehead just above his nose. The bite started out looking like a typical insect bite smaller than the size of a dime but it has continued to swell and is now the size of a quarter. We have used Cortizone cream, Neosporin which did nothing. Last night I had him apply peroxide on it followed by a warm compress. The swelling went down and the pain subsided somewhat but the spot looks more like a scab now. We continue to put peroxide and warm compresses on it but my husband says he feels like a stinger or something is still in there. I think he should see a doctor but he doesn t want to. I fear it might be a brown recluse bite. We don t have a clue what might have bitten him since we didn t spend much time outside that weekend. I should add he has just recovered from lung cancer after having his left lower lobe of his lung removed and underwent low dose/mild chemo.