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.
Moreover, you can apply a paste of neem leaves as well. The honey and cinnamon paste works as a good home remedy for acne, even on the scalp, when applied for 15-20 minutes. Follow this treatment two to three times in a week for a few months. Honey has antimicrobial properties. Thus, it inhibits the growth of bacteria.