it completely depended on the type of mask you are using. It is important to ensure that the mask is fitting well. If you are combining your CPAP therapy device with a leaky mask, then it is surely going to dry out your nose. In case you need to tighten your straps quite often to prevent air leakage, then be sure about the fact that your mask is not fighting properly. Thus, problems like nose drying or stuffy nose can easily occur.