>>>  Does anyone have any idea of any other causes/treatment
>>>for a milk blister that is stubborn and doesn't respond to the usual?

Melody,

I worked with a mom last year who had chronic nipple blebs/blisters as
well as full blown feverish mastitis and regular plugged ducts.  (The
only thing that kept her going was baby's intolerance of formula.)  I
plotted out all her episodes at about 3 months postpartum and noted that
the blebs stopped and the longest clear period for her was after tx with
Diflucan for yeast.  (just one dose that time and based on vaginal
symptoms).  This chart helped me get the Dr. to prescribe Diflucan again
a couple months later when the same symptoms developed without the
vaginal symptoms.

 I'd never heard of the connection between blebs and yeast before that.
Then I was re-reading the new LC series on Candidiasis and Breastfeeding
and guess what?  They talk about white spots on the nipple as one
possible symptom!

After that I recommended aqueous gentian violet whenever mom had episodes
and it helped. (mom couldn't tolerate any breast creams due to
allergies--nor could she tolerate alcohol based meds on the skin.)

 [ This mom also tried lecithin and was on a multiple food elimination
because of the baby's sensitivities.  (which reminds me, eliminating
peanuts and chocolate and caffeine has helped some moms with this)]

Natalie Shenk, BS IBCLC
private practice in Ohio