A white spot in the back of the throat is a common symptom, representing a localized collection of material on the tonsils or pharynx. This material is typically inflammatory debris, pus, or calcified matter. While many underlying conditions are minor, these spots can signal a bacterial, viral, or chronic issue that may require medical evaluation.
White Spots Caused by Acute Infections
White spots that appear suddenly and are accompanied by systemic illness often point to an acute infection. The most common bacterial cause is Group A Streptococcus, responsible for strep throat. The white spots are typically streaks or patches of purulent exudate on the tonsils, formed by the body’s immune response. This is frequently accompanied by a sudden onset of fever and severe throat pain.
Viral infections, such as infectious mononucleosis (Epstein-Barr virus), can also cause white spots resembling bacterial exudate. Mononucleosis often produces prominent white patches and significant swelling of the tonsils, coupled with extreme fatigue, body aches, and swollen lymph nodes. Unlike bacterial infections, these viral causes do not respond to antibiotics and require supportive care.
A fungal infection, known as oral thrush (candidiasis), presents as creamy, cottage-cheese-like white patches that can appear anywhere in the mouth or throat. Caused by an overgrowth of the yeast Candida albicans, it often affects individuals who are immunocompromised or have recently taken antibiotics. A distinguishing feature is that the patches can often be gently wiped away, sometimes revealing a reddened area underneath.
Non-Infectious and Chronic Causes
Not all white spots result from an active infection; some are chronic formations of debris. Tonsil stones (tonsilloliths) are small, hard, yellowish-white deposits that form in the tonsillar crypts (crevices on the tonsils). These stones result from the calcification of trapped food particles, mucus, dead cells, and bacteria. They are not contagious and are often associated with chronic bad breath (halitosis). Unlike infectious exudates, tonsil stones are firm and do not cause a systemic fever.
Another non-infectious cause is leukoplakia, which appears as a persistent, thick, white patch that cannot be scraped away. Leukoplakia is often linked to chronic irritation, most notably from tobacco use, and is considered a potentially precancerous lesion. Any white patch that remains for more than two weeks should be investigated by a healthcare provider. Rarer causes include aphthous ulcers (canker sores), which are white or yellow with a distinct red border, though they usually form on the softer tissues of the mouth.
Evaluating Severity and Accompanying Symptoms
The context of the white spot provides important clues about its origin. A high fever, generally over 101°F, strongly suggests an acute bacterial or severe viral infection. Significant difficulty or pain when swallowing (dysphagia) indicates severe inflammation. Swollen and tender lymph nodes in the neck are a common sign of a body-wide immune response.
The duration is also a key differentiator; acute infections typically resolve within ten days, while chronic conditions like tonsil stones or leukoplakia persist longer. The ability to wipe the white patch away suggests a fungal cause (oral thrush) rather than a fixed lesion (leukoplakia).
Diagnosis and Treatment Options
A healthcare provider begins diagnosis by taking a patient history and performing a visual inspection. For acute symptoms, a rapid strep test or throat culture determines if the cause is Streptococcus bacteria, which is crucial since treatment protocols vary significantly. If the infection is bacterial, antibiotics are prescribed to eliminate the bacteria and prevent complications. Viral causes, such as mononucleosis, are managed through supportive care, including rest, hydration, and pain relievers. Confirmed oral thrush requires specific antifungal medications.
For tonsil stones, treatment is often unnecessary unless they cause discomfort or chronic bad breath, and may involve gargling with salt water or manual removal. Leukoplakia requires close monitoring and sometimes a biopsy to rule out malignancy, especially if the patch persists after removing the source of irritation, such as quitting tobacco use.