Obvious see a doctor, but chances are they wil diagnose it from finding pictures that resmebe it. So look for yourself on google images for skin problems. But see a doctor. I paid a doctor, consultant and was expensive, he diagnosed it from pictures on his database.
Nil cost just write it photograph you writing it and completed and holding it up to camera. Keep it simple as you can. Thailand recognizes and upholds this type of will, holographic.
Shows the calibre of some of the posters on here. Dishonourable duckers and divers without a pot to piss in. No wonder Thai wants to upgrade the dross clogging up the tourist trade. ""Don't pay rent"" idiots