She wasn't certain that it is yeast, because it isn't particularly "wet" (more dry like excema patches) but it is spreading to his belly in a pattern that looks yeast-like. And she noted that his skin (on his face by his cheeks, his legs etc.) is a little on the dry side so maybe that was why his possibly yeasty rash was more dry than expected.
It is such a stubborn rash.
Lately, though, it doesn't seem to be affected or exacerbated by poop. I mean, if I don't catch a poop right away, he gets irritated. But the last few times, his poops have mostly been at the back (didn't even get to the skin at the front) and the rash remains worse at the front of his pelvis....covering the front of his crotch/groin, and spreading up to his stomach and starting to speckle his chest.
The underside of his scrotum has some very red patches, and his perineum is red (those places are more in contact with poo when he poops) but his butt cheeks are mostly clear at this point.
I just took antibiotics for stubborn plugged ducts that had progressed to mastitis and just weren't getting better (I have exclusively nursed twins for 7 months, and then introduced solids gradually....they are almost 9 months now) and finished the course today. But he had this rash before that (abx) was a factor. I am giving him powdered probiotics in water, but didn't start until I was nearly through with the antibiotic (I should have thought of it earlier and I had them on hand, but it just was an oversight....seriously, it is very hard for me to get from point A to point B a lot of the time.)
He also has dry patches of skin at the tops of his thighs that sometimes get very red and radiate a rash downward onto his legs. This particular rash started up after he wore a cotton diaper (Under The Nile organic fitted) overnight in long wool pants. He had the dry patchy rash on his thighs, and a bright red speckled rash all over inside the diaper and spreading up at the waistband area.
He's been in disposables since then but it hasn't really cleared up.
He definitely has been the more sensitive baby where skin/rash issues are concerned, and also where poop is concerned (more likely to have green poops or mucousy poops with any changes in feeding even when exclusively bfing....such as if I cut a feed short, when we were nursing in a waiting room or restaurant or something like that, any kind of possible foremilk/hindmilk imbalance.) His brother would have the thick whipped yellow poops and his poops would be thinner, very vinegary smelling, sometimes green. He did have more consistently thicker poops eventually, but any little variation or deviation and I'd see it in his diaper.
I assigned them to a breast, switching sides each day, because of this baby. At four months when the same pooping issues started up again in a more regular way, I assigned them a breast and stopped switching sides at all. He has gotten rashes or had problems, including with creams themselves.
I've tried using barrier creams (various ones with zinc oxide but no petroleum products) but he's always seemed to react to them, at least after awhile. At a certain point with this rash, since the skin was so broken, I stopped trying barriers and covered his skin with a Vaseline-like coating of "Un-Petroleum Jelly" which sort of worked.....it cleared up the thigh stuff and his skin seemed moisturized there. The stuff on his groin seemed calmer, but still there. Then the angry-red thigh rash reappeared, the diaper rash worsened again, and the more dramatic belly-spread happened.
I thought the rashes on his cheeks/chin were food related, as I gave avocado and he got pink spots very soon after (I wasn't sure if it was the cloth wipe I cleaned him up with or the food, but the next time I gave avocado it was the same.) So I cut back on solids with him (he hadn't had much yet, anyway. I have gone very slowly with this twin because his system seems so sensitive and I didn't want to see lots of mucous in his poops.) So he would play with toys at the table and his brother would eat. But then I started seeing the "sudden" rash on his cheeks even when he wasn't eating ANYthing (just nursing.) I began to think it was more of a drool rash (he is getting his second tooth....I saw the literal cut in his gum today and that's what happened right before his first tooth popped through last month.)
He seems prone to excema, maybe sensitive to stuff through my milk (I have never really tried any elimination or anything), and so I am reluctant to treat for yeast with a prescription cream, but I don't want to prolong his problem rash either.
He is really pulling and scratching at himself with every diaper change, and seems bothered.
I'm sorry for the long post....just trying to brainstorm and provide information that might prompt something helpful.
Checked both babies for thrush at the appointment and both looked good.