Simultaneous pancreas-kidney (SPK) transplantation is the primary surgical treatment for type I diabetes mellitus with end-stage renal disease. However, this transplant surgery has a high-risk of surgical complications, including duodenal anastomotic leakage, which may lead to pancreas transplantation failure if the leakage worsens. This case report describes a patient who suffered from duodenal anastomotic leakage after SPK transplantation. The digestive enzymes eroded the wound and skin around the wound, resulting in periwound moisture-associated dermatitis. During the period of nursing care, the wound-care intervention was determined by interdisciplinary cooperation. In our case report, the periwound moisture-associated dermatitis healed completely under inter-hospital care. In clinical nursing practice, periwound moisture-associated dermatitis should be cared in combination with macerated wounds. We suggest the following: (1) control the moisture source; (2) use advanced dressings as the primary dressing with sterile gauze as a secondary dressing and silver antimicrobial dressings for infected wounds; (3) consider using negative pressure wound therapy for complicated chronic wounds; and (4) use a pH-neutral skin cleanser with non-woven gauze to clean the periwound skin and keep the skin clean and dry. Finally, we suggest isolating and protecting the skin with No Sting Barrier Film and a hydrocolloid dressing. We hope this nursing care experiences serves as a reference for the nursing care of periwound moisture-associated dermatitis resulting from duodenal anastomotic leakage during / after SPK transplantation.