Thanks for writing here.
Dandruff is a fungal infection
occuring at teen age.At times it can be severe.You need a good antifungal shampoo like nizoral.Use it twice weekly.You can also apply antiboitic cream like clindamycin
over the affected area.For sensitive skin use a mild cleanser like cetaphil
.Avoid sun exposure. Consulting a dermatologist
will be better option.
Hope this will help you.Take care.