Chemotherapy-Induced Oral Mucositis Clinical Presentation

Updated: Mar 14, 2023
  • Author: Nathaniel S Treister, DMD, DMSc; Chief Editor: Jeff Burgess, DDS, MSD  more...
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Patients may initially describe generalized burning or sensitivity of the oral mucosa about 1 week after starting chemotherapy. With onset of frank ulcerations, patients typically report pain, which can be quite severe. Oral pain contributes to patient morbidity. Difficulty with eating, drinking, speaking, and maintenance of oral hygiene regimens typifies morbidity. Additionally, oropharyngeal and esophageal involvement is common and may precede the onset of oral ulcers. Some patients with severe mucositis may require parenteral nutrition until they are better able to swallow adequately. Dysgeusia, or altered taste sensation, may further reduce the patient's appetite.

Oral mucositis begins 5-10 days following the initiation of chemotherapy and lasts 7-14 days. Therefore, the whole process lasts 2-3 weeks in more than 90% of patients. Resolution (in the case of hematopoietic cell transplantation [HCT]) coincides with recovery of the WBC count, specifically when the absolute neutrophil count becomes greater than 500 cells/µL (see the Absolute Neutrophil Count Calculator). In patients being treated for solid tumors, the duration of oral mucositis depends on the type, dose, and course of treatment. Patients undergoing HCT conditioned with total body irradiation are at somewhat higher risk of experiencing more severe and prolonged oral mucositis.


Physical Examination

The oral cavity should be examined, using an adequate light source, on a daily basis for inpatients and at every clinic visit for outpatients. All oral mucosal sites should be assessed; therefore, it is important to have the patient move his or her tongue and to retract the buccal mucosa to visualize the posterior aspects and buccal vestibules.

The earliest changes in chemotherapy-induced oral mucositis are those of leukoedema, although these changes cannot always be appreciated. These changes present as diffuse, poorly defined areas of pallor or milky-white opalescence most noticeable on the buccal mucosa. These areas disappear if the mucosa is stretched. This is followed by erythema (see images below) and atrophy on the mucosa that may then break down to form ulcers that are covered by a yellowish-white fibrin clot (the pseudomembrane). Ulcers may range from 0.5 cm to greater than 4 cm in maximum dimension. At the height of oral mucositis, patients experience marked pain, difficulty opening the mouth, difficulty with any form of oral intake, and difficulty with mouth care regimens.

Erythematous oral mucositis lesion on the buccal m Erythematous oral mucositis lesion on the buccal mucosa.

The mouth is a trauma-intense environment. When the oral mucosa becomes atrophic from chemotherapy and renewal of oral epithelium has been slowed, local trauma leads to ulceration, with nonkeratinized sites being the most vulnerable. Therefore, lesions occur bilaterally, mainly on the nonkeratinized sites in the mouth, namely the buccal mucosa, the ventral and lateral parts of the tongue, the labial mucosa, the floor of the mouth, the soft palate, and the oropharyngeal fauces (see images below). Because many patients (especially those undergoing HCT) are profoundly thrombocytopenic, bleeding may occur from sites of ulcerative oral mucositis.

Ulcerative oral mucositis lesion on the buccal muc Ulcerative oral mucositis lesion on the buccal mucosa.
Ulcerative oral mucositis lesion on the lateral an Ulcerative oral mucositis lesion on the lateral and ventral surfaces of the tongue.
Ulcerative oral mucositis lesions on the labial mu Ulcerative oral mucositis lesions on the labial mucosa and the floor of the mouth.

Patients treated with methotrexate as part of their graft versus host disease (GVHD) prophylaxis are also at increased risk; non–methotrexate-containing regimens have been associated with lower rates of mucositis. [15]

A dry mouth (xerostomia) from decreased salivary flow (hyposalivation) secondary to chemotherapy reduces natural lubrication and contributes to the ease of trauma-induced ulceration, difficulty in eating and swallowing (dysphagia), and the accumulation of debris in the mouth. In general, this is of much greater concern in patients undergoing radiation therapy to the head and neck, which, in addition to causing significant salivary gland hypofunction, is also associated with significant rates and severity of oral mucositis. A hairy tongue and superficial mucoceles may develop as a result of decreased salivary flow and limited oral intake (see the images below). Hairy tongue is not a candidal infection. Retention of keratin on the filiform papillae of the tongue from hyposalivation, alteration of constituents of the saliva, and eating a soft diet or not eating at all contribute to the development of hairy tongue. While retention of keratin on other sites, such as the gingiva and hard palate, may also be mistaken for oral candidiasis, hyposalivation changes the intraoral milieu and predisposes to candidiasis so that the conditions may coexist. Candidiasis is less likely when patients are on antifungal prophylaxis.

Hairy tongue. Hairy tongue.
Multiple mucoceles on the hard palate. Multiple mucoceles on the hard palate.


A wide range of complications are associated with oral mucositis, including, but not limited to, the following:

  • Inadequate pain control
  • Poor nutrition
  • Dehydration
  • Interruption of cytoreductive therapy
  • Increased length of hospitalization
  • Increased cost of treatment
  • Increased risk of local and systemic infection

Oral mucositis is a painful condition, which, when severe, may require intensive pain control and nutritional support. In the context of HCT, severe oral mucositis has been associated with increased overall hospital costs and hospital length of stay. [16] If oral intake is severely limited, patients may become dehydrated and require intravenous support. Patients with severe and prolonged oral mucositis, for example in the context of HCT, may require total parenteral nutritional support.