A dressing for a negative wound pressure therapy system includes a patient interface layer, a first fastening layer, a second fastening layer, and an upper cover. The patient interface layer defines an opening. The first fastening layer is coupled to the patient interface layer. The second fastening layer is detachably coupled to the first fastening layer such that the second fastening layer can be separated from and reattached to the first fastening layer while still forming a substantially airtight seal with the first fastening layer. The upper cover is coupled to the second fastening layer and covers the opening.