hello madam, these are may be due to hormonal imbalance.please gently exfoliating and moisturizing the affected area. Certain home remedies such as lemon juice, aloe vera, yogurt and cucumber may also help brighten darkened skin. please check your blood sugar level. diabetes can cause these symptoms. if u are obese, try to reduce by regular exercise.obesity can cause these symptoms. Hydroquinone creams are available over the counter and in prescription strength. Do not use hydroquinone for longer than three months. If the treatment is effective, you can expect to start seeing results after four weeks. Hydroquinone can cause skin irritation, burning, stinging and redness in some individuals. Stop using the cream if you experience severe irritation or swelling. Corticosteroid creams that contain ingredients, such as hydrocortisone, can help fade areas of dark pigmentation and reduce the chance of skin irritation associated with other topical treatments.