Ill-fitting, removable prosthetic appliances can traumatize oral mucosa and increase the risk of microbial invasion into deeper tissues. Denture-soaking cups can readily become colonized with a variety of pathogens, including P. aeruginosa, E. coli, Enterobacter species, Staphylococcus aureus, Klebsiella species, and Candida albicans. Dentures should be evaluated before chemotherapy begins and adjusted as necessary to reduce risk of trauma. Denture-cleansing solutions should be changed daily. In general, dentures should not be worn when the patient has ulcerative mucositis and is neutropenic (i.e., absolute neutrophil count <500 cells/mm3).
Candidiasis is typically caused by opportunistic overgrowth of C. albicans, a normal inhabitant of the oral cavity in a large proportion of individuals. Several variables contribute to its clinical expression, including drug- or disease-induced immunosuppression, mucosal injury, and salivary compromise. In addition, use of antibiotics may alter the oral flora, thereby creating a favorable environment for fungal overgrowth.
A systematic review indicated that the weighted mean prevalence of clinical oral fungal infection during chemotherapy is 38%. The most common forms of intraoral candidiasis reported in oncology patients are pseudomembranous and erythematous candidiasis.[20,21] Pseudomembranous candidiasis can usually be diagnosed on the basis of its characteristic clinical appearance and may be accompanied by burning pain and taste changes. The appearance of erythematous candidiasis is relatively nonspecific, and laboratory testing may be needed to confirm the diagnosis. It may be accompanied by a burning sensation of the affected tissues.
Topical oral antifungal agents such as nystatin rinse and clotrimazole troches are often used but appear to have variable efficacy in preventing or treating fungal infection in neutropenic patients.[22,23] Patients who wear removable dental prostheses (e.g., partial or full denture) should remove them before the oral antifungal agents are used. Dentures can also be treated by soaking them overnight in the antifungal solution.
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.