I too have the same issue. On top of thickened skin that peels on my thumb, my thumbnail is brittle. I've been dealing with this for about 4 years. I've tried tea tree oil, nail fungus treatments, etc. I decided to have my nail tested for a fungus and it came back negative. The strange thing is the test showed a high level of yeast. So after researching my symptoms further I'm going to try some of the suggestions I've read. I found three that seemed promising. 1.Threelac and Oxygen Elements Plus 2. Symbion Probiotics. 3. Vitamin A & B Complex along with immune building herbs. Keep you posted! KP