Yes these pigmentation are likely post inflammatory hyperpigmentation.
Chemical peels can be done over these areas. In this way, skin turnover is stimulated and lightening of these pigmentations are facilitated.
Non-ablative laser eg. NdYag laser also help with these pigmentations. It has to be a gentle laser setting, which will not worsen the pigmentation, but instead help to break down the melanin deposits. Many sessions of laser will be required.