My son has pimples on forehead.

The severity of acne dictates the choice of treatment. In the early grades of acne even the cream might suffice however in moderate to higher grades tablets also need to be taken. The treatment has to be continued for a few months otherwise the pimples would tend to return easily. Kindly do not self medicate without professional advice as that could further damage your skin.You can use Salsa KT lotion as shampoo for now. But you need to get your scalp properly examined to know whether the excessive flaking is because of seborrheic dermatitis or an inflammatory condition like psoriasis. Kindly do not delay the treatment and get a consultation done with a qualified dermatologist how are you can get an online consultation privately with pictures if you wish. Hope this is helpful.