Wow, not really the answer I expected, but thank you for the information. I live up in Phetchabun and no one up there seemed to have a good idea.
Sheryl, I think I have read over the years that you are in Chiang Mai. While doing and internet search before posting my question I found a link to Bangkok Hospital Chiang Mai advertising a "medical dermatology clinic." It mentions checking for skin cancer. Have you any information about Chiang Mai?
BTW, I have appreciated your grounded advice about medical topics over the years. This is the first time I have chimed in to a discussion with you. Keep up the good work and thanks.