Hello. Thank you for writing to us I suggest a possibility of fronto-parietal morphea/ Linear scleroderma. This condition presents with a ivory colored vertical band of hard bound, atrophic/ sclerotic skin, usually on one side of the forehead and may extend up to Or even beyond the anterior hair line. It is a chronic condition and may gradually extend. It is a self limiting condition i.e the process ultimately stops after a time, however, it may be disfiguring. The atrophy may extend to deeper levels to involve subcutaneous tissue as well as bone. Deeper involvement to the level of bone, is usually felt as a dent/ ridge. Since you also notice a ridge in that area, probably the process has extended to underlying to bone as well. Treatment is with topical potent steroids and oral steroids if the disease is still active and progressing. I suggest that you visit a dermatologist for a confirmatory diagnosis as well as appropriate prescription. Regards