Stretch marks can appear when there is rapid stretching of the skin. It is common in rapid gaining or losing of weight, pregnancy, puberty, cushings syndrome and overuse of steroids.
Creams containing alpha hydroxyl acids and retin-A are said to be useful in decreasing the stretch marks but the advertised antimarks creams have no proof of effectiveness. Eat healthy, nutritious food ,drink plenty of fluids and do moderate exercises. Laser therapy and dermabrasion, alone or in combination have also been shown to be effective in diminishing the appearance of stretch marks. For that you need to consult a dermatologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
Not sure if that would cause it. I would try cocoa butter and vitamin E see if it helps.