Disclosed embodiments may relate to dressings configured to provide negative-pressure wound therapy to a tissue site, while simultaneously shielding a portion of the tissue site from the negative pressure. For example, dressing assembly embodiments may comprise an outer dressing configured for applying negative-pressure wound therapy to a tissue site, and an underlying isolation patch configured for use under the outer dressing. The isolation patch may be configured to seal the portion of the tissue site so that it does not experience the negative pressure. Additionally disclosed are other apparatus, dressings, systems, and methods.