Thanks for the query posted
I would be pleased to answer your query .
You condition seems to be due to certain Liver
Liver enzymes and Bile acid
in the blood can give rise to a lot of itching and rashes on the body at your age group .
Further investigations into the cause of the raised enzymes levels should be done .
You should book an appointment with the Dermatologist
and Hepatologist for the same .
Thanks and Take care