What Causes Rashes All Over With Swelling And Itching?

hi doctor,

I am lakshmi and i am 30 years old. I am a nursing mother. Recently i have developed some kind of rashes in almost 10 different places in my body whic ia itching badly. At one place in my hand i thought i had an insect bite which got swollen a bit and was itching. after two days it has developed into a small kind of pimple and with reddish area around it. Similar rashes are seen in other parts of the body. kindly advice. Thank You