The appearance of a sore or lesion on the tonsils often causes concern, as the throat is a sensitive area involved in speaking and swallowing. Tonsil ulcers can be a painful symptom of various conditions, ranging from common infections to more serious, systemic issues. Understanding the cause of these lesions is the first step toward appropriate care. An accurate diagnosis is important because the underlying cause determines the course and severity of the condition.
Defining Tonsil Ulcers and Lesions
An ulcer is an open sore that forms when the surface tissue, or mucous membrane, breaks down and fails to heal properly. On the tonsil, this results in a loss of the protective lining, exposing the underlying, sensitive tissue. True tonsil ulcers typically appear as small, distinct lesions with a white, yellow, or gray center surrounded by a red halo of inflammation.
It is helpful to distinguish a true ulcer from other lesions, such as vesicles (fluid-filled blisters that may rupture to become an ulcer) or the white patches characteristic of some infections. Ulcers are often intensely painful, particularly during swallowing. They can sometimes be mistaken for the white exudate seen in bacterial tonsillitis. The pain can interfere significantly with daily activities like eating and drinking.
Common Infectious Causes (Viral and Bacterial)
The most frequent causes of tonsil ulcers are infectious pathogens, with viruses representing the majority of cases. The Epstein-Barr Virus (EBV), which causes infectious mononucleosis, can produce severe inflammation and ulcerative lesions that may be mistaken for a bacterial infection. Another common viral culprit is the Coxsackievirus, which causes herpangina, characterized by the sudden onset of fever and small, painful ulcers or vesicles on the soft palate and tonsils.
Herpes Simplex Virus (HSV) can also manifest in the throat, creating painful sores that begin as small blisters before breaking open into ulcers. While not causing true ulcers, the bacterium Streptococcus pyogenes (strep throat) causes significant tonsillar inflammation and white exudate, which is sometimes confused with ulcers. A more serious bacterial complication is a peritonsillar abscess, a pus collection near the tonsil that causes severe unilateral throat pain and difficulty opening the mouth.
Inflammatory and Autoimmune Manifestations
When inflammatory or immune processes are the cause, the resulting lesions may be recurrent or systemic. Aphthous ulcers, commonly known as canker sores, are painful, non-contagious sores that can appear on any soft tissue in the mouth, including the tonsils. These ulcers are triggered by factors like minor trauma, nutritional deficiencies (such as B12 or iron), stress, or food sensitivities. They typically heal within one to two weeks.
More complex causes involve systemic inflammatory or autoimmune disorders where the body mistakenly attacks its own tissues. Behçet’s disease is one such condition, characterized by recurrent, painful oral ulcers that are often the first symptom. These ulcers appear alongside other manifestations like genital sores and eye inflammation. They are caused by inflammation of the blood vessels (vasculitis), and their recurrence differentiates them from acute infectious sores.
Serious and Non-Infectious Causes
While less common than infections, certain non-infectious factors can cause tonsil ulcers, some of which carry serious implications. Physical trauma is a frequent cause, often resulting from scraping the throat with hard or sharp food items, like chips or crusts. This trauma creates a mucosal break that forms a traumatic ulcer. These lesions usually heal quickly once the source of irritation is removed.
Certain systemic treatments, such as chemotherapy or radiation therapy, can damage the rapidly dividing cells of the mucosal lining, leading to painful ulcers throughout the mouth and throat. The most concerning non-infectious cause is malignancy, specifically tonsil cancer (a type of squamous cell carcinoma). A cancerous tonsil ulcer is typically non-healing and often unilateral (affecting only one tonsil). It may also be associated with a persistent sore throat or a lump in the neck.
Diagnosis and When to Seek Medical Attention
Diagnosing the cause of a tonsil ulcer requires a careful review of symptoms and a physical examination of the throat. A healthcare professional may perform a rapid swab test or culture to check for bacterial infection, such as Streptococcus. They may also order blood work to look for viral markers, such as those for mononucleosis. For recurrent or unusual ulcers, further investigation may involve blood tests for nutritional deficiencies or systemic conditions.
Immediate medical evaluation is necessary if an ulcer persists for more than two weeks without healing, as this is a key warning sign for serious conditions. Other concerning symptoms, or “red flags,” include severe difficulty swallowing or breathing, a high fever, extreme unilateral pain, or a noticeable, firm mass in the neck. These symptoms suggest a need for urgent attention to rule out complications like a peritonsillar abscess or malignancy.