Hello,
You have history of having 
hepatitis C. You have taken treatment but are suffering from 
white spots on the skin that have got worse and are spread on your arms and thighs. The toxins that build up in your blood and cause symptoms can also make you itch. The symptoms sometimes appear after years of the infection. To treat the condition, you’ll need to treat the hep C infection and 
liver damage that’s causing it.
Hepatitis C and its treatment can cause dry, itchy skin, too. Take home made balanced nutritious food and take water after boiling when it gets cooled. Prefer to take boiled food over spicy, oily fried food. Avoid full fat dairy products, 
trans fat, red meat, refined flour. Take more fruits, berries, veggies, lean meat and small fish. Take food rich in Zinc or zinc supplements to get rid of the skin problem you are suffering from,
To reduce discomfort you can take oatmeal baths and apply water based  moisturizers thereafter. Antihistamines and applying 
cortisone creams bring relief, too. Quit 
smoking and addictions if any. Protecting your skin from direct exposure to sunlight will help. You can get it clinically examined by a 
dermatologist if needed.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Nupur K., General & Family Physician