Hi Kreisha and welcome to HCM
Since you do have a history of
psoriasis, it would definitely be a possibility in the lower back or sacral area.
But it could also be a
fungal infection. Before applying steroids on the area for psoriasis, it would be better to get a skin scraping for fungus done or
consult a dermatologist to rule out fungal infection, as infection would require different treatment.
You could apply an antifungal like
clotrimazole or
terbinafine cream twice daily till you see the doctor, and watch for improvement, Also you can take an antihistamine to help with itching.
But if it is psoriasis you can take your regular medication that you usually use. For this reason, see your doctor as soon as possible before the disease gets worse or new patches erupt.
A new drug, change in weather, travel, certain foods, etc could have brought up the psoriasis again. So do take care.
Hope this helps.