Take a warm shower before bed every night. Wash your hair with shampoo for scalp psoriasis (with tar, ketoconazole, or salicylic acid). If your doctor gave you medicine to use during your shower, put it on your wet scalp before you shampoo. Leave it on for the prescribed period of time, then wash and rinse. Always use conditioner to help keep your skin moist. After your shower, gently rub any creams or scale softeners into your scalp. Put a dry shower cap over your hair before bed. This will keep it damp and hold medicine in.