Although topical agents may be helpful for superficial oral candidiasis, systemic agents should be used for persistent fungal infections and in patients with significant immunosuppression. Systemic fluconazole is highly effective for prophylaxis and treatment of oral fungal infections in the oncology population.
Noncandidal fungal infections
An increasing number of different fungal organisms are being associated with oral infection in immunocompromised cancer patients, including infection by species of Aspergillus, Mucormycosis, and Rhizopus.[3,23] The clinical presentation is not pathognomonic; lesions may appear similar to lesions caused by other oral toxicities. Microbiologic documentation is essential. Systemic therapy must be instituted promptly because of the high risk of morbidity and mortality.
Herpes group viral infections, including those caused by oral lesions, can cause a variety of diseases that range from mild to serious conditions in patients undergoing treatment for cancer. The severity and impact of these lesions and systemic sequelae are directly related to the degree of immunocompromisation of the patient. Comorbid oral conditions such as mucositis or graft-versus-host disease can dramatically increase the severity of oral lesions and significantly increase the difficulty of diagnosis.
In most instances, herpes simplex virus (HSV), varicella-zoster virus (VZV), and Epstein-Barr virus (EBV) infections result from reactivation of latent virus, while cytomegalovirus (CMV) infections can result from either reactivation of a latent virus, or via a newly acquired virus. The viral infections can cause oral mucosal lesions. The prevalence of HSV infection was found to be higher when oral ulcers existed than when no oral ulcers were present.
A systematic review was conducted by the Mucositis Study Group (MSG) of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology. One of the aims of this review was to evaluate studies conducted since 1989 that considered the prevalence of oral viral infections. The reported prevalence of oral HSV infection was 49.8% (95% CI, 31.3–68.2%) among neutropenic cancer patients. The prevalence was much lower in head and neck cancer (HNC) patients who were treated with radiation therapy (0%); however, it rose to 43.2% (95% CI, 0–100%) in irradiated HNC patients who were treated with radiation therapy combined with chemotherapy. This finding is not surprising because neutropenic patients—mainly patients with hematological malignancies—develop deeper immunosuppression during cancer treatment than do other groups of cancer patients. However, the addition of chemotherapy to the conventional radiation therapy increased risks for HNC patients.