It is nothing like they cannot be treated, they can be done by naturally preparing them at home some of which are listed here:
1. Almonds and milk:
Soak some almonds in water for about 12 hours, now peel the skin off and make paste from them by adding little milk. Now this paste has to be applied on the blemishes to be left on for about entire night, first thing in the morning is to wash this paste off with cold water. This process has to be repeated for complete 2 weeks.
2. Potato:
Take a small potato slice and rub it on the skin blemishes for about 10 minutes, this has to be done for daily twice or thrice to see effective results.
3. Mint leaves:
Make fine paste from few mint leaves and apply it on the blemishes. Leave the paste for about 20 minutes before rinsing with cold water.