Spark ignition gasoline and compression ignition diesel engines differ in how they supply and ignite the fuel. In a spark ignition engine, the fuel is mixed with air and then inducted into the cylinder during the intake process. After the piston compresses the fuel-air mixture, the spark ignites it, causing combustion.
1 If your skin is too sensitive, dilute tea tree oil with some baby shampoo. Add 10-20 drops of tea tree oil to 1/2 cup of baby shampoo. Use this daily to wash your scalp and hair till you get rid of itchy scalp.  You can even massage diluted tea tree oil to your scalp.
Adding foods rich in vitamin A to your diet might help improve skin health, alleviating scalp itch. Foods that are good sources of vitamin A include eggs, butter, dairy products, sweet potatoes, squash, carrots, cantaloupe and papaya.itamin A is essential to skin and scalp health, according to the Linus Pauling Institute Micronutrient Center; Vitamin A plays important roles in the immune system and blood circulation as well as supporting the maintenance and function of skin cells.