Pimple like bump on side of foot that are itchy. bumpy but itches like a mosquito bite. what is this?

Hard to say without: seeing it. It could be a contact rash to something. Is it only on one foot? Any new creams, lotions, shoes? Do you have the rash anywhere else? I would recommend that you have it seen by your primary care doctor or a dermatologist, so that it can be diagnosed properly. Or if you are signed up for HealthTap Prime, you may be able to consult with one of us that way and send a photo.