What causes darkening of facial skin?

Question
I am a 30 years old HIV infected person and my skin colour is getting darkened day by day. My complexion used to be fair before I was infected, but nowadays my skin colour or complexion (only on the face) is getting darker. Are there any creams that can help or is that any medication reaction?
Expert Answer
K
Darkening of the facial skin can occur in any chronic illness, from undue sensitivity to light, after any other inflammation of the face like allergy to cosmetics, seborrhoea etc. Use a simple sunscreen for a few days. If no improvement is seen in a few weeks, then consult a dermatologist.
Expert Answer
D
Please consult your treating physician to know the exact cause of the skin discoloration.