My mother has a strange skin infection rash?

Possibly for a spider bite, but we have no idea. It began as only as a kind of mosquito bite lump'ish, redness etc. Now it has small pustules that look like little pimples .. Is there anything that could be? Is it contagious? We have no idea what to do or what it is, but apparently it's just very sore when touched they bite, but then others it is simply painful

I do not think it's contagious, but an insect bite can turn into cellulitis or infection. Seing as it is painful and has pustules, would his eye doctor in the same. Meanwhile, consider Neosporin or antibiotic ointment on it or warm / hot wet compresses.

New Treatment for Psoriasis and Dermatitis