Although allogeneic hematopoietic stem cell transplantation is potentially curative for various disorders, it carries the risk of GVHD. Patients who do not have an HLA-matched donor are at higher risk for GVHD, but they can still potentially undergo transplantation with strategies that are intended to mitigate this risk. In general, those with more severe, grade 3 or 4, acute GVHD are more likely to develop cGVHD, and these patients will invariably have some form of skin or mucosal manifestation. The skin is one of the most important targets for GVHD, both acute and chronic, and it is the first and most frequently affected organ.  

cGVHD often presents as areas of skin disturbance, sometimes as very specific itching and dryness of the skin and other times as just thickening of the skin at the places of pressure, such as where a belt or a bra strap goes. You can see the development of morphea-type scleroderma or thickening of the skin when it becomes leathery in those areas. There are a variety of diagnostic pathologic findings, including poikiloderma of Civatte, lichen planus, and scleroderma-type skin changes that can be seen with cGVHD. The oral and vaginal mucosae can be considered as, essentially, extensions of the skin, and many patients develop mucosal ulcerations in addition to having skin involvement. 

For many mild manifestations, such as a mild limited rash, local treatments may be needed. For more severe manifestations or for disseminated manifestations, however, systemic immunomodulatory or immunosuppressive therapies may be essential. Clinicians can consider some form of topical therapy that will serve to spare the patient from receiving systemic therapy, such as steroids. Although steroids are effective, they can cause significant problems for patients in the long-term, including infections, which are a major cause of death in patients with cGVHD. In those who are requiring high doses of steroids to maintain disease control, serious consideration should be given to adding one of the second-line agents, such as ruxolitinib, belumosudil, or ibrutinib, as a steroid-sparing strategy to try to reduce the long-term side effects of these agents. 

Chronic steroid use is also associated with dermatologic toxicities such as skin thinning and ecchymosis. This can cause skin breakdown and predispose patients to infections. Proper education of patients and caregivers and prompt attention to skin breakdown are important aspects in healthy skin management, as is continued dermatologic screening for skin cancers. Patients who have had a transplant have a higher risk of developing secondary skin cancers, and they should be monitored appropriately. These individuals should be careful with sun exposure because there are many medications that produce photosensitivity, and this increases their risk of developing certain skin cancers.