My leg itches and gets pimples when I scratch it

A scratch on the leg itch pimples, is due to the skin, mucous membrane reactive expansion of small blood vessels and permeability increased and produced a localized edema reaction, known as artificial urticaria. Show the pimple and scratch, about half an hour later can be self-subsiding. There are also some people who show late-onset artificial urticaria, showing no discomfort when scratching, showing symptoms after a few hours, usually 6 to 8 hours when the symptoms are most serious, this uncomfortable symptom generally does not exceed two days. Artificial urticaria can be self-healing, usually a few weeks or 2 or 3 years time can be self-healing, self-healing will not show symptoms after scratching. Alternatively, cetirizine, loratadine, etc. can be used under the guidance of a doctor.