Picture shows hyper pigmented skin lesions in a woman aged 68 years. There are multiple patchy lesions over the whole of medial aspect of thighs and lower part of abdomen. Lesions are non itchy and not scaly. Remain for 2 or 3 months and disappear on their own without any specific treatment. It is appearing on and off for the past 5 years. Dermatologist consultation was sought. Advised moisturizer and multivitamins with no effect.

She is a well controlled diabetic on metformin 500 mg twice daily. No other health issues. All blood tests are normal CBC, smear, renal and liver tests. No h/o allergy. What could be the further management of these hyper-pigmented skin lesions?