How do you approach Pityriasis rubra pilaris that is retinoid resistant?  

I find most PRPs to respond, at best, incompletely to retinoids - they are not my first line. Any TNF-alpha or IL-12/23 inhibitor is reasonable to try, and there are no head-to-head trials to my knowledge to endorse one other. Mtx may need to be added. IL-17s likely work too for some patients. Depen...

Agree with IL17 and IL23 first but if these fail would look into this recent well-done study published a few months ago. To summarize, in a precision medicine approach, they conducted transcriptomic and IHC analyses on PRP skin samples vs psoriasis, AD, controls. They identified IL-1β as a pivo...

I go for IL17 or IL23 first. Agreed that retinoids are not great for this, although "first line" in books and some literature.

I agree. For adult PRP, Il17i works within a few months. A retinoid can help bridge therapy for patients who may want faster clearance. I’ve done Isotretinoin + IL17i and then tapered off Isotretinoin.