What is your treatment algorithm for dissecting cellulitis of scalp?

I view dissecting cellulitis as a variant of HS (and we know it's a component of the follicular tetrad along with acne conglobata and pilonidal cysts). Anti-TNFa inhibitors and isotretinoin are preferred therapies for this condition with a high level of efficacy.

I agree totally. I start with cultures and appropriate antibiotics and move to isotretinoin when the inflammation is down, then typically to Humira.

...and occasionally Kenalog, usually intralesionally or occasionally IM.

Oral antibiotics probably give the quickest response, and chronic therapy may be required, including antibiotics, oral isotretinoin, biologics, and surgery.