We've consulted a couple of vets
Our Shih Tzu's exhibited symptoms of sebaceous adenitis for more than 2 years now. It's been only of cosmetic concern, thankfully.
Her hair loss is on either side of her abdomen, accompanied by "hyper-pigmentation," areas of very dark skin. I apply a coconut oil-based moisturizer every few days to those areas, even though they're not really all that dry. And she gets the Omega supplements everyday, on her food and in a vitamin-rich paste she laps out of my hand.