My Grandaughter Is Visiting. She Has Very Thick Hair And

my grandaughter is visiting. She has very thick hair and I noticed a thick sheet of dandruff on her scalp, I also noticed that her scalp is a little lumpy. I do not know if it is sores. It is not moist but ther is lump behind her right ear at her hair line. How do I get rid of the dandruff and what is the lump behind her ear. She is 10 years old.