Brief Answer:
Undergo certain tests to find the cause

Detailed Answer:
Hi
Thanks for being at healthcaremagic
Itching without rashes has multiple causes. The most common ones being iron deficiency anaemia, thyroid disorders, liver and kidney diseases and senile pruritus that is itching in elderly individuals.
Treatment of itching depends on the cause and to find it out you need to undergo certain tests:
complete blood counts
liver function tests
kidney function tests
thyroid function tests
Swelling of the feet and ankle can be due to heart disease or kidney disease.
You need to consult a doctor and get yourself examined clinically
Meanwhile in such cases I recommend my patients to take antihistaminics till the time the cause is identified.
I recommend them to take tablet Chlorpheniramine 4 mg once or twice daily depending on the intensity of itching.
I hope to have answered your query and would be happy to clarify any further doubts.
Regards
Dr Asmeet

---