Scalp itches can occur because of two major reasons: particle pollutants emitted from industries and vehicles can settle on the scalp.
When these get dissolved in sweat and reach the scalp’s dermal layer, they can cause irritations, and these are felt as itches. Scratching the itchy spot would certainly help for easing the problem.
Second type of scalp itch can occur due to dry dandruff. When we allow forceful jets of shower water to hit the scalp , the sebum (oil) from the oil glands tend to get removed, thus leaving the scalp dry without any oil.
Similar to the curling of the surface clay in a drying pond, the dried outer layer of the scalp peels and curls. These constitute the dry dandruff.
The sebaceous oil is a powerful germicide. In its absence, airborne bacteria gain entry into the spot and start feeding on the dandruff. Such bacteria tend to give us the scalp itch.
Scratching the scalp when itch occurs due to dandruff may not be a good idea, for it only aggravates the situation by increasing the peeling process and spreading of the bacteria.
In this case, the best remedy should be to replace the sebum. In other words, some gingerly oil application to the scalp would rectify the problem very well.
The excess oil can be removed from the hair with the use of some good shampoo. While doing this, the oil on the scalp should not be removed by over-rubbing the scalp, or with the use of excessive shampoo.
There is another type of dandruff called ‘wet’ dandruff, and this looks like flakes, and oozes out from within. This has nothing to do with the shampoo nor with the shower water.
This type of wet dandruff is due to the accumulation of excessive calcium in the body. Therefore, we have to eliminate the excess by the procedure I have been repeatedly describing in this book in different contexts.
See Hair Problems, Psoriasis, and Itch on Skin and Scalp.