Well, i'll try not to overwhelm you with info, but the gist of it is that at birth, a baby's immune system is neutral. If born vaginally, they get a good drink of (hopefully) good bacteria that's in your gut flora. If your gut flora is out of balance, the drink can be not so good. And if born by c-section, they don't get the drink at all, plus they get a bad start b/c of the antibiotics (anti-life) given to the mom at the birth. My girls were c-section. Plus i think i've had an imbalance of too much bad flora / bacteria (very common actually, especially in women - do a search on candida) for 10 years. Your gut is filled with good and bad flora at all times, but sometimes things can throw off the imbalance - like taking antibiotics, being on the pill (or other things that effect hormones), even the hormones from being pregnant, eating too much sugar and simple carbs, etc. My girls didn't have thrush, but they had signs of yeast in their diaper area and armpits...also spit up a lot, and had eczema, and bad cradle cap- also colic. Our ped. said that eczema is most commonly a food sensitivity, or a yeast (candida) issue - usually points to a weak digestive system of some sort. SO.... What we chose to do was go the long route to recovery...through diet. Took lots of PROBIOTICS - (pro-life) to help establish good bacteria. Our ped said probiotics and diet are the best way to get at it for good. Creams don't get to the root cause. Many Dr's prescribe something like Nystatin - again, my Ped tends to wait to see if diet will remedy it first. Trouble is the diet takes FOREVER to see results - 3 to 6 months of no sugar or carbs (even limited fruit). Which is fine for a baby, but if you breastfeed, they get the stuff through you. And i think it's common for the mom to have it anyway.
BUT, we're on the other side of things now. Did the diet for 4.5 months, and we are YEAST FREE! Eczema's gone, digestion has improved (and so have other things - like bowel movements, etc for my 18 month old). My 3 year old is still getting a red diaper area now and then. But skin is such a good barrier for germs, that once it's broken, it can pick up other things easily. so it's hard to tell what really is causing the rashes, yeast or something else.
ANYWAY, that's enough info for now! I can It can be very overwhelming at first....i had to switch dr's to find one who was more holistic, cause my first one didn't even bring any of this up. Course i didn't know about any of this until i switched dr's, but i just wasn't satisfied with "this is common, she'll grow out of it."
Oh - i should also say, that we also are dealing with milk protein allergy. both dd's would scream while nursing if i had a big bowl of ice cream beforehand, so that was fairly easy to see. but with dairy elimination for me, i still didn't notice the eczema go away...just happier nursing.
I hope you're able to discover what's causing the eczema!