While COVID-19 is primarily a respiratory disease, the infection can lead to various manifestations outside of the lungs. These presentations include dermatological and mucosal changes, such as the development of sores and lesions within the mouth. Oral manifestations are now recognized as a potential symptom of the disease. Recognizing these signs and understanding their underlying causes is important for managing the full scope of a COVID-19 infection.
Identifying Oral Lesions Associated with COVID-19
Mouth sores linked to COVID-19 are diverse, but they are most frequently reported as aphthous-like ulcers, commonly known as canker sores. These ulcers typically present as painful, shallow lesions with a creamy-white or yellowish center surrounded by a distinct, bright red, inflamed border. The size of these lesions is often small, resembling minor aphthae that measure less than one centimeter in diameter.
Herpetiform lesions are another common type, appearing as clusters of small, fluid-filled blisters that quickly rupture to form erosions. While they mimic the visual pattern of herpes, they are not caused by the herpes simplex virus. Generalized inflammation is also observed, such as glossitis, which involves a swollen or depapillated tongue, sometimes presenting with indentations along the sides.
The tongue is the most frequently affected site, accounting for up to 38% of reported cases. Lesions are also commonly found on the inner cheek (buccal mucosa), the inside of the lips (labial mucosa), and the hard or soft palate. These symptoms can appear at various times, sometimes developing 4 to 7 days before typical systemic symptoms, or weeks after the initial infection. The widespread presence of multiple sores or ulcers that are unusually painful can be a distinguishing feature of COVID-19 related oral issues.
Understanding the Underlying Causes
The development of mouth sores during a COVID-19 infection is believed to result from a combination of direct viral activity and the body’s aggressive immune response. The SARS-CoV-2 virus gains entry into human cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor. ACE2 receptors are expressed in the oral cavity, particularly on the epithelial cells of the tongue and salivary glands, making these areas susceptible to viral attachment and potential infection.
The immune response involves a hyper-inflammatory state, often called a “cytokine storm,” which can inadvertently damage healthy tissues. The release of inflammatory molecules, such as Tumor Necrosis Factor-alpha (TNF-\(\alpha\)), triggers aphthous ulcers by causing inflammation and cellular damage in the mucosal lining. This systemic inflammation can also lead to vasculitis (inflammation of blood vessels), contributing to ulcerative lesions.
Sores can also arise from indirect factors accompanying severe illness. Stress, compromised oral hygiene, and certain medications contribute to the breakdown of the oral mucosa. Immune suppression can lead to opportunistic infections, such as a flare-up of herpes simplex virus or an overgrowth of the fungus Candida albicans (thrush), which then manifest as painful lesions.
Managing Discomfort and Promoting Healing
Managing discomfort from COVID-19 related mouth sores focuses on pain relief and creating an optimal environment for tissue repair. A fundamental home care strategy involves maintaining gentle but consistent oral hygiene to prevent secondary bacterial infections. Rinsing the mouth several times a day with a warm saltwater solution can soothe irritated tissues and aid in healing.
Dietary adjustments are important to prevent mechanical and chemical irritation of the lesions. Temporarily avoid foods and beverages that are spicy, highly acidic (like citrus fruits or tomatoes), or very rough and crunchy. A soft, bland diet minimizes trauma to the sores during chewing and swallowing. Hydration is also beneficial, as drinking plenty of fluids helps prevent dry mouth, a condition known as xerostomia, which can exacerbate oral soreness.
For targeted relief, over-the-counter topical anesthetics (gels or creams) can be applied directly to the sores to numb the area before eating. Protective pastes that coat the ulcer can also shield it from friction and irritation. If the pain is more widespread or severe, mild systemic pain relievers or anti-inflammatory drugs may be considered to reduce overall discomfort.
In some cases, a healthcare provider may prescribe specialized mouthwashes containing ingredients like chlorhexidine, or mild corticosteroids to reduce inflammation. Antiviral or antifungal agents may also be prescribed if a secondary infection is suspected. Consult a doctor or dentist if the lesions are severely painful, prevent eating or drinking, or show signs of a worsening secondary infection.