We advice to start with treating a small spot with Kartalin to see how the skin reacts.
Allergic reactions to Kartalin are very unlikely. If you do get an allergic reaction you should wash the Kartalin off immediately and consult your general practitioner. A solution to allergic reactions could be to use antihistamine for the first couple of weeks to surpress any allergic reactions. Always start with a small spot if you are treating spots on a sensitive area such as the skin.