Melasma treatment with chemical peels. How often can I get them done?

Melasma continues to be a difficult problem for many women. 
The TCA peels should help but beware that this is no rookie" peel and your provider MUST have experience or you could get burned. 
Lytera is a newer lightening/bleaching agent compared to hydroquinone.  It takes longer to work, which could possibly be why you feel that it doesn't work if you have tried it. I promise you that it does work and it also takes longer to "wear off" if you stop. This is good if you run out of product and wish to avoid the "flare" phenomenon that is often associated with stopping hydroquinone.
Also for you to consider is the PICOSURE laser.  It is one of the only lasers that are FDA-approved for treating melasma and I believe is the newest of them.
Best wishes!
Dr. Cayton

Melasma is one of the hardest conditions to treat.... try this-1. Lytera nightly2. TCA 8% every 2 weeks at a Specialist clinic3. Low fluence 1064 QLS by either plastics or derm. This should help get you around your irritant- allergy to HQ. Kind regardsDr Davin LimLaser dermatologistBRISBANE, Australia.