No, it is not advisable to use topical steroid cream for scalp psoriasis. Rather, you would complicate the case by doing so. It will only go from the surface, and get suppressed into the body. You can consult your current doctor and ask for a homoeopathic ointment of the same medicine that you are taking orally.
Next Steps
You can also consult me online on Practo to discuss your case history in detail, including mental health, find out the cause of your psoriasis and get proper homoeopathic medicines.
Health Tips
Only apply aloe vera gel or coconut oil for relief if you have itching.