It sounds like your daughter may have some sort of skin infection; it is advisable that you take her to a doctor for a check up. If necessary, your doctor may recommend visiting a dermatologist for a specialized opinion. Since you have not mentioned any really unpleasant symptoms such as itching or burning, you can try a few things at home, but if they do not work, be sure to visit a doctor.
First of all, you can try applying any topical anti fungal medication on the affected areas. You can simply as for an anti fungal cream or ointment at the drug store. This should be applied twice a day (or as per the instructions on the packaging) for at least two weeks. If what you have described is a fungal infection, there is a good chance that this treatment will be effective and the spots will disappear, or at least decrease in number or intensity within around two weeks. If you are unable to get an anti fungal cream or ointment, or if for some reason you prefer not to use such medications, you can try using a natural anti fungal such as tea tree oil. Tea tree oil should be easily available at any store that sells herbal or organic products. This should be applied in the same way as described above, for the same period of time.
It may be that your daughter is simply experiencing an unusual case of dry skin. During the teen years, hormone levels are fluctuating, and skin growth is sometimes abnormal. Your daughter's skin may be discarding cells too fast, or may not be discarding cells properly, resulting in the white spots and dryness. For some reason, your daughter's torso may be the only area affected by this problem. If this is the case, then the problem is only temporary, and should be easily managed with some simple measures. (However, to be on the safe side, you should get a confirmation from a doctor. If there is an infection, then it will be much more difficult to treat later on.) When bathing, your daughter should use a loofah - this helps in removing the upper layer of dead skin, and helping new, healthy skin to come to the surface more quickly. Immediately after bathing, your daughter should apply a moisturizing cream or lotion. This will trap the moisture that has already been absorbed by her skin, thus minimizing the chances of dryness.
answered by M W