I use Ketoderm cream on my face for seborrheic dermatitis, but my skin seems to lose its elasticity, becomes red and flakes. Is this normal? Should I continue the cream?

After symptoms including redness, itching and scaling on my chin, on my lips and around my lips since November, I concluded that it was probably seborrheic dermatitis. I was first advised to try Canesten, which was unsuccessful (symptoms worsening). I was then advised to apply La Roche-Posay's Cicaplast baume B5 twice a day (morning and evening) as well as Cicaplast lip balm when needed. The result was relatively satisfactory, but unfortunately the problem tended to recur at the slightest omission of application of cream, to then take several days to diminish without disappearing completely, the problem is not solved, I rather have the impression to simply mask it (to send it "under the carpet"...). I then went to see my doctor, who also concluded that it was seborrheic dermatitis, and prescribed me Ketoderm 2% cream, to be applied twice a day (morning and evening) for 4 weeks. I started the treatment on March 1st, however, where I apply the cream (chin and around the lips), my skin has become reddish and abundantly scaly again in only a few days, which is how it looked before I applied La Roche-Posay Cicaplast. I also feel like my skin is pulling, as if it has lost its elasticity. Is it normal for Ketoderm to cause such a side effect? According to the list of side effects, the cream can irritate locally, however I don't feel that it is particularly irritated, but only extremely dry and covered with perpetual flakes (particularly unsightly, in the face), there is no more itching than before, but I don't dare scratch the flakes for fear of removing the layer of cream. Is it risky, or is it worth applying a moisturizer like Cicaplast over the Ketoderm? Is this side effect worth continuing the treatment for the next 4 weeks or is it better to stop immediately (risk of after-effects?)? Are there any solutions to reduce the flaking and redness while treating the problem in depth and not just on the surface? For further clarification, I have never needed to use any moisturizer on my face before (only on my hands), I never wear makeup and I usually don't use any product on my face except lip balm during winter, as my lips tend to chafe. For any medication, I take oral contraceptives (Alesse) and consume daily Metamucil (since December, so probably has no link with my current problem since it started in November) for persistent diarrhea problems since taking antibiotic (penicillin) in April 2016 following a flu. Unfortunately impossible to prove if my intestinal dysbiosis problem has any link with the one on my face... A huge THANK YOU to whoever can answer me!!!

Thank you so much for the information! So I'm going to give it a shot and use Cicaplast following the Ketoderm application, crossing my fingers that it reduces the flaking.