What are the possible causes of skin darkening around the face, neck, and hands?

Hi,

Welcome to icliniq.com.

There are numerous reasons for getting a dark face and neck. It would have been better if you had also sent an image. However, I am suggesting medications based on the description:

1. Apply sunscreen with SPF (sun protection factor) 30 before going in the sunlight.
2. Apply Vitamin C cream at night.
3. Take the capsule Perfectil (vitamin E, vitamin C, folic acid, biotin, magnesium, iron, zinc and selenium, Grape Seed extract, and L-Cysteine) once daily.
4. Take treatment for atleast two to three months.

Consult a specialist doctor, discuss with them, and take medications with their consent.