Is there any cure for skin writing? what medicine or preventive measures to take to reduce it.

Dermatographism: Assuming you mean the condition that if you apply pressure or use your finger even on the skin, you can actually "write" on the skin, then this is a hypersensitive skin condition. The cure is simply avoid doing acts that will cause the reaction. The reaction when occurs, will usually resolve in time and is not permanent, so the condition is not considered life threatening, but is unique.