This presentation can be seen with many diseases. This is limited information to make precise recommendations. The best option is to consult a Dermatologist to understand the condition. A thorough evaluation if necessary should be done. Hope it helps you.
Next Steps
The best thing that you can immediately do for yourself is to stop Panderm.
Health Tips
Skin already tanned can be treated with de-pigmenting creams and other oral medications. A good skin care regimen comprises 4 steps - cleansing, toning, moisturizing and sun block. Based on your skin type, a dermatologist will recommend you appropriate products.