<s>[INST] I have a rash that appeared on my arm a few days ago. First it was red bumps I thought were mosquito bites but they didn t itch until I put alcohol on it. The next day it spread down my side lightly aND at the top of my other arm. What could this be?? [/INST] Hi,It may be lichen urticatus..also called papular urticaria.Consult the dermatologist for the perfect diagnosis and proper treatment.It may be due to hypersensitivity reaction to insects.Take antihistaminics like levocetirizine 10 mg daily. You may also take oral steroids in tapering dose. Apply soothing lotion like calamine lotion. Keep away yourself from insects. Avoid contact with soap.Hope this helps.Dr.Ilyas Patel MDDermatologist </s>