Why when I have my shampoo allergic reaction I get pimples on my face? My face is very clear I never breakout just until I started with my itching.

Contact allergy. If you are allergic to one or more ingredients in the shampoo, you may develop skin lesions 24 to 72 hrs after. You will need to try different shampoos to find which one does not affect your skin. If the problem persists, then see a dermatologist who may perform some patch skin test on you. In the meanwhile , you may use topical Hydrocortisone to clear up the rash.