Face

I had an allergic reaction to some medication my face turned really red now that the redness has gone it left my face looking darker around my mouth and cheek area what can I use to get the color back to normal?

[Dr_Aparna]

Hi,
This is a condition called post-inflammatory hyper pigmentation. It is a discolouration that is left on the skin after an underlying skin disease has healed (like allergic reactions,  
mechanical injuries or reactions to medications).

It is more common in darker skinned individuals. You should use a good broad spectrum sunscreen daily to reduce further darkening.
Usually, hyperpigmentation will gradually lessen over time and normal skin colour will return. However, this is a long process that may take up to 6-12 months or longer.

You can use skin lightening agents such as Hydroquinone or Tretinoin cream.  Glycolic acid peels and Azelaic acid are also effective in reducing the increased pigmentation.
Usually a combination of the treatments suggested is required for significant improvement to be seen.
ref:http://dermnetnz.org/colour/postinflammatory-pigmentation.html