What are some causes of extreme itchness in toddlers.?

Also... I agree with dr kwok's response. But in rare cases uncontrolled itchiness can be caused by metabolic conditions such as liver disease, so a doctor's consultation may help.
A few causes. Dry skin or sensitive skin, as in eczema, can be quite itchy without an obvious rash. Wearing wool clothing can be very itchy. Toddlers can also itch after rolling around in the grass and on carpets or rugs. Rashes such as hives and healing chicken pox or sunburns can lead to lots of itching. Scabies rash are extremely itchy, with kids scratching skin bumps until they start oozing or bleeding.