Was the 50% TCA Chemical Peel Too Strong?

After a 50% TCA I would expect your whole face to be red, swollen and tender (not just your cheeks). If there is pus or oozing then you need a topical prescription antibiotic such as Bactroban 3 times a day. Most redness and swelling at 5 days is to be expected and can easily be treated with prednisone 20 mg twice a day and a topical steroid cream such as triamcinolone cream 0.1% twice a day.
Blisters and sores around the mouth would indicate a reactivation of your cold sores or fever blisters which would require anti-viral pills but it doesn't sound like you have that. See your doctor and have him evaluate you to see if you need something special. Most people will panic after a stronger peel and really only need reassurance that everything is going according to plan.
After you finish healing, then I would be surprised if you didn't notice a significant difference in your skin. Be patient. Hopefully you will be pleasantly surprised in the end and won't give up on chemical peels since they are so important in keeping your skin healthy and young looking.
Sincerely,
David Hansen, MD

TCA 50% is considered a deep peel. With this percentage of TCA, there can often be unpredictable scarring and pigmentary issues which is why many have stopped using it. If you just had this peel. be judiocus with cleaning and keeping the area moist. I would recommend silicone based creams as this can minimize some of the scarring (ie. stratamed OR Silagen). If it has been several months/ years since the treatment, you may need secondary peels/ laser such as IPL, BBL, or Fraxel to help lighten scarred/ pigmented area. It is likely to take several rounds of treatment and topical creams to help minimize the chance of repeat scarring and pigmentation. Also, I would recommend seeing a healthcare provider who is skilled at treating  this or has the experience.

In my practice I routinely do 35% TCA peels. I do not suggest TCA Peels more aggressive than this because the risk becomes significant. For patients who need something more aggressive than a 35% TCA Peel, I would suggest a different, safer alternative such as Laser Peel.

Redness, swelling and some crusting for 7-10 days after an aggressive chemical peel is expected, but worsening redness after 5 days is concerning for possible infection e.g. cellulitis. A contact dermatitis or other complication is also possible. I would advise you to follow up immediately with the individual who applied the peel (if he or she is a qualified practitioner experienced in dealing with post-peel complications). The faster a post-peel complication is appropriately managed, the lower the risk of long-term scarring and pigmentary problems.

I hate to second guess qualified physicians, so my first question would be if your friend is a board certified dermatologist or plastic surgeon familiar with aggressive peels and how to manage the wound healing period and any complications.
50% TCA is aggressive and seldom used (but not incorrect under certain circumstances) because of safer options of layering peeling agents of lesser concentration. The other issue is who compounded the TCA and how old is the batch since it can get more concentrated if expired.
Please always make sure all options are discussed before treatment. A laser or lighter peel may have been fine to accomplish your needs.
Please go back and see the treating physician who can manage your unusual complaint post-procedure.
Good luck!