Dry scalps on babies are normal and often treatable at home. In most cases, the underlying cause is cradle cap.  Dandruff, eczema, and allergies are other possible causes. But in most severe cases if left untreated can cause future issues. 

When your scalp's natural moisture balance is disturbed, an itchy, dry irritated scalp can be the result. A dry and itchy scalp can be associated with ageing or skin conditions such as Atopic Dermatitis or Psoriasis, and its symptoms can range from very mild to extreme.