The general causes of itching are;
1) Dry skin; happens in the winter months; baby Johnson oil or any moisturizer would help.
2) Skin allergy
3) Kidney, and liver disease (it is termed as pruritus); investigations would be needed to ascertain it. Please read the causes of itching in this authentic resource;
http://www.mayoclinic.com/health/itchy-skin/DS00847/DSECTION=causes
Following investigations are usually advised;
a) Complete blood counts
b) Total eosinophil count
c) Vacuolated eosinophil count
d) Liver function tests especially serum bilirubin
e) kidney function tests (blood urea and serum creatinine)
Now we come to uncommon causes;
A) Hematologic pruritus; thrombocythemia, iron deficiency, polycythemia, hypereosinophilic syndrome.
B) Endocrine pruritus; due to thyroid and parathyroid diseases, diabetes, etc.
C) Malignancies. Carcinoids, Lymphomas, and leukemias.
You may need the following investigations, if not done;
Skin biopsy
Serum protein electrophoresis
Stool for ova and parasites
Stool for occult blood
Peripheral blood film.
Urine for hydroxy indole acetic acid (5-HIAA) and mast cell metabolites.
The treatments which can help are;
Topical cannabinoid agonist creams
Naltrexone,
Ondansetron,
Colestyramine,
Thalidomide,
Corticosteroids,
Mirtazapine
Paroxetine
UV-B light therapy.
So you need investigative work up to get to the root cause of it. You may apply a good moisturizer meanwhile.
I hope your symptoms resolve soon.
I would be happy to assist you further if you need more information.
Thanks for using JustAnswer.