Oral chronic graft-versus-host-disease (cGVHD) has a significant impact on patient quality of life and dental health, so early recognition and treatment is a priority. Future therapies may include photobiomodulation, microbiome-targeting therapies, and preventive approaches.

The mouth is an organ that patients are very aware of, and, while they might not recognize if they are experiencing oral cGVHD, it is fairly easy for a physician to recognize it once the patient reports signs or symptoms. Individuals with oral cGVHD can present with xerostomia and often have sensitivity to spicy, acidic, or hot foods. They can develop mouth ulcers that they might misinterpret as being canker sores. Other things, such as an outbreak of oral herpes simplex virus (HSV), can also mimic oral cGVHD. And, since patients with oral cGVHD are immunosuppressed, they are more prone to developing oral HSV outbreaks. Most patients take prophylactic medicines to avoid that from happening, but it is certainly in the differential diagnosis.

At times, at my institute, we refer patients with oral cGVHD to a dedicated oral medicine specialist who is part of our multidisciplinary team. Early recognition leads to better long-term outcomes, and patients really need to have routine and regular oral monitoring for the complications associated with oral cGVHD.

It is important to try to differentiate active cGVHD from the sequelae of oral cGVHD. For example, it is unlikely for a patient to have active oral cGVHD 10 years following a transplant. What is more likely in that time period is patients having things like chronic xerostomia and the complications that go along with that (eg, accelerated oral cavities and issues with eating and swallowing). Patients with oral cGVHD can also have scleroderma of the mouth and a narrowing of the oral aperture, which is very difficult to reverse, even in the long-term.

Patients who have received an allogeneic hematopoietic stem cell transplant have a higher rate of developing oral malignancies. These patients may be at an even higher risk of developing oral malignancies if they have oral cGVHD. We recommend at least annual—if not twice-annual—dental visits for all patients who have had a transplant as part of good survivorship care.

We are just starting to learn about the oral microbiome and its role in oral cGVHD. We know that the microbiome of the gastrointestinal tract is altered in cGVHD, and it is reasonable to believe that the oral microbiome may also be altered. It is unclear if an altered microbiome may lead to oral cGVHD or if chronic xerostomia may lead to an altered microbiome.

There are a number of topical and systemic therapies available for oral cGVHD, and we are testing new localized therapies. Photobiomodulation is being tested for both the prevention of oral mucositis and the treatment of cGVHD, but, right now, the data are mostly from small studies.

We think that prevention is going to be far more important than therapy. Oftentimes, by the time a patient with oral cGVHD presents with and complains of xerostomia, they have already lost a substantial proportion of their salivary gland function, and it is unclear how much is reversible. That is why prevention is worth more than treatment.