Henna does not cause opend sores and blisters.
Black henna has PPD in it which can cause sores and blisters and also land you in the hospital.. So do not use it its dangerous to health.
If you buy ready made mehndi cone always find out what chemicals they use in mixing the henna powder. Somtimes if you are allergic to certain types of oils find out if these oils are used many times clove oil is used in mixing. so be sure to find out to avoid the nasty allergy.
