Your question is extremely vague — you have not mentioned your daughter's age and, more importantly, where this internal itching is. Most probably you are referring to vaginal itching. There are several possible causes for this, but the most common one is some sort of vaginal infection. Bacterial and fungal infections of the vagina are quite common. Apart from itching, such infections are usually accompanied by other symptoms such as an unpleasant odor, abnormal discharge, inflammation, and burning, discomfort, or pain, particularly when urinating. However, itching may also be due to a condition known as atrophic vaginitis, which is not due to any infection but is the result of a lack of the estrogen hormone. Here too, knowing your daughter's age would help in forming a diagnosis. Although this condition can affect women of all ages, it most commonly occurs during and after menopause. The symptoms of this condition also include itching, burning, and abnormal discharge, as well as dryness.
The remedy for your daughter's condition will depend on its cause. It is best that you visit your family doctor for an examination and diagnosis. Once the doctor determines the cause of the itching, he or she will be able to prescribe the appropriate treatment.
answered by G M