Reddish rash with blisters may be contact or allergic dermatitis. Fungal infections, psoriasis and seborrheic dermatitis may present with redness and some degree of scaling. If the rash hurts, there may be an underlying infection present. Apply thinly 0.05% fluocinonide cream over the area. Be careful not to apply over broken
skin. Apply once daily for 3 days and on the 3rd day , see if any improvement is noted. You may need to have this assessed by your doctor so that the right medications may be given.The differentials I have mentioned require different forms of management.