White patch on my head. Is hair growth?

I recently shaved my hear and i can see some areas of my head show white dots or white patch specially in the middle and i do have itching issues . Basically there is uneven scalp with white dots . Is it some kind of infection. Will it affect my hair growth or will it lead to some else problems. I had suffered from dengue before two years around September of 2019 since then i do have suffered from dandruff issues not that severe but it is continued from then ,is it because of that. Also i have recently used organic shampoo of biotic which immediately used to dry my scalp and make my hair hard , unable to be combed ,is it because of that. Also i do always have itchy scalp . The patches are not that severe but white dots all over the middle part of scalp and on those dots there is hair growth