If I were you, I would also try
alt.med.veterinary

Is it in and around her ears too? Does it take fur with it when a
scab comes off? Does she have sneezing fits? Respiratory problems?
My cat's disease might have been misdiagnosed as pemphigus first
before it was diagnosed as eosinophilic granuloma complex. That
was 5 years ago. After treatment, we have been using a
high-quality air filter. She's doing marvelously better nowadays
but she is at least 10 years old and has developed another
occasional symptom that sounds like she is trying to clear her
sinuses. I suspect shampooing the carpets will help, will see.

Good luck.