Can Leukemia Cause Mouth Ulcers?

Understanding the Link Between Leukemia and Oral Ulcers

Mouth ulcers are a common but often overlooked symptom that can be associated with leukemia. While many people assume oral sores are simply due to stress or minor infections, they can sometimes signal a more serious underlying condition—such as leukemia. In patients with this blood cancer, mouth ulcers may develop due to two primary reasons: the disease itself and the treatments used to manage it.

Oral Ulcers Before Treatment: A Sign of Weakened Immunity

In untreated leukemia, one of the main factors contributing to mouth ulcers is a severely compromised immune system. Leukemia disrupts the normal production of healthy white blood cells, which are essential for fighting off infections. As a result, the body becomes highly susceptible to bacterial, viral, and fungal invasions in the oral cavity. This weakened defense mechanism often leads to recurrent or persistent mouth sores that are slow to heal and may be accompanied by bleeding gums or oral discomfort.

Chemotherapy-Induced Mucositis: A Common Side Effect

Another major cause of oral ulcers in leukemia patients is chemotherapy. Many anti-cancer drugs, such as methotrexate, interfere with rapidly dividing cells—including those lining the mouth. Methotrexate specifically inhibits folate metabolism, a process crucial for DNA synthesis and cell repair. When this pathway is disrupted, it results in oral mucositis, characterized by painful ulcers, inflammation, and tissue breakdown inside the mouth.

How to Manage and Reduce Oral Ulcer Symptoms

Proper oral hygiene plays a critical role in minimizing the severity and duration of mouth ulcers. Patients are often advised to rinse their mouths with saline solution several times a day. This simple practice helps cleanse the oral cavity, reduce bacterial load, and soothe irritated tissues. Using soft-bristled toothbrushes and avoiding alcohol-based mouthwashes can also prevent further irritation.

The Role of Rescue Therapies in Chemotherapy Patients

For those undergoing treatment with high-risk medications like methotrexate, targeted interventions can help mitigate toxicity. Leucovorin (also known as folinic acid) is commonly used as a "rescue agent" to reverse or prevent methotrexate-induced mucosal damage. Administered under medical supervision, it supports healthy cell function without interfering with the drug's anti-leukemic effects.

When to Seek Medical Advice

Persistent or severe mouth ulcers should never be ignored—especially in individuals with a known cancer diagnosis. Early intervention can prevent complications such as secondary infections or difficulty eating and speaking. Always consult a healthcare provider for an accurate assessment and personalized treatment plan. Self-medication should be avoided, and all therapies should be guided by clinical evaluation and professional medical advice.