Anything wrong with treating my weekly seborrheic dermatitis just outside ear canal with triamcinolone?

Try hydrocortisone. Seborrheic dermatitis of nonscalp regions is extremely steroid-responsive, and therefore potent fluorinated steroids need not be used. Moreover, since the face and body folds are often involved, prescribe a nonfluorinated (nonatrophogenic) steroid (eg, desonide 0.5%, alclometasone dipropionate cream, or hydrocortisone 2.5% cream) to be applied twice daily or 3 times daily.