I think your cousin had some allergies which have left behind scars
. On the scars, you can start using adapalene
ointment 0.1% and Hyseac ointment locally on the scars every alternate night. So basically, on 1 night, your cousin should use adapalene and the next night Hyseac. this needs to be done for atleast 6-8 weeks.
If it doesnt respond, see a dermatologist
, Glycolic peels etc are some of the options we have for scar removal
Hope that helps