Gum Boil
Parulis
A gum boil, also known as a parulis, is a small swelling or lump on the gum that is often associated with underlying dental infection. It may appear as a pimple-like lesion that can release fluid, and symptoms can vary — some individuals experience discomfort while others have little or no pain. A professional dental assessment is important to identify the cause and determine appropriate management.
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Understanding the Condition
What Is a Gum Boil (Parulis)?
A gum boil — clinically referred to as a parulis — is a localised swelling or pimple-like lesion on the gum that forms as a result of an underlying infection. It often develops as the body creates a drainage point for pus accumulating within deeper tissue, allowing the fluid to escape into the mouth.
In most cases, a gum boil is a visible sign of a dental abscess — a collection of infection either at the root of a tooth or within the gum tissue. The appearance can vary: some boils are small and white, others are red or yellow, and they can range in size from a tiny spot to a noticeable swelling. The lesion may come and go as it drains.
Because a gum boil indicates active infection, it should always be professionally assessed. A thorough dental examination — usually supported by X-rays — helps identify the specific source, which then guides the most appropriate course of treatment.
Symptoms & Warning Signs
Small lump or pimple on the gum
The most recognisable sign — a raised, often pimple-like swelling on the gum surface, typically near a specific tooth
Discharge of pus or fluid
The boil may intermittently release pus or clear fluid, which some patients notice as a bad taste or a small amount of discharge in the mouth
Bad taste or unpleasant odour
Active infection can produce a persistent unpleasant taste or odour, particularly if the boil is draining into the mouth
Tenderness or throbbing discomfort
The area around the boil may feel tender, sore or throb, especially when pressure is applied or when biting down on nearby teeth
Associated tooth sensitivity or pain
The tooth linked to the infection may feel sensitive to hot, cold or biting, or may cause ongoing discomfort that does not settle
Swelling of surrounding gum tissue
The gum around the boil may appear red, swollen or inflamed, and in more advanced cases swelling may extend into the face or jaw
A gum boil should not be ignored, even if it is painless or appears to drain on its own — it is typically a sign of an underlying infection that requires professional assessment.
Contributing Factors
Common Causes of a Gum Boil
A gum boil is almost always a sign of infection — but the source can lie in different areas. Identifying the underlying cause is essential in determining the right treatment.
Dental abscess from an infected tooth
The most common cause — an infection that has developed within or around a tooth (often due to deep decay or trauma) can create pressure that forces a drainage tract through the gum, appearing as a boil
Untreated tooth decay
When decay progresses through the enamel and dentine into the pulp, bacteria can infect the nerve and blood supply of the tooth, leading to infection that may drain as a gum boil
Gum disease (periodontal infection)
Advanced gum disease can create deep pockets around the teeth where bacteria multiply. Infection within these pockets can produce a gum boil even when the tooth itself is not decayed
Cracks or trauma to the tooth
A cracked or fractured tooth can allow bacteria to reach the inner pulp, leading to infection and the formation of a gum boil as the body attempts to drain the affected area
Previous dental treatment requiring review
In some cases, a previous root canal or crown may develop an infection over time, or an area of trapped debris near a restoration can contribute to gum boil formation
Foreign body or localised irritation
Occasionally, a foreign object lodged in the gum — such as a food particle or a fragment from previous treatment — can cause localised infection that presents as a gum boil
Why It Matters
Potential Risks if Not Addressed
Because a gum boil reflects active infection, leaving it untreated allows the underlying infection to persist. Although the boil may appear to drain and reduce temporarily, the source of the infection usually remains, and the lesion typically recurs — often with increasing discomfort over time.
Without treatment, infection can gradually spread to surrounding tissues — including the bone supporting the tooth, other areas of the gum, or more distant structures. Significant spread of dental infection can lead to facial swelling, systemic symptoms such as fever, and in rare cases more serious complications that require urgent medical care.
Ongoing infection can also cause damage to the affected tooth and its supporting structures, potentially reducing the likelihood that the tooth can be saved. Addressing the cause at an early stage — through prompt dental assessment — typically offers more treatment options and helps minimise further impact on oral and general health.
Your Options
Treatment Options for a Gum Boil
Treatment depends on clinical assessment and the underlying cause. Management varies based on diagnosis, and a personalised treatment plan is recommended following professional evaluation.
Emergency Assessment
Prompt clinical review is often the first step — identifying the source of infection and relieving any acute symptoms through an emergency dental appointment.
Learn MoreDrainage of Infection
Where appropriate, the dentist can drain the abscess to relieve pressure and reduce discomfort as part of initial care. This is a treatment of symptoms rather than the underlying cause.
Learn MoreRoot Canal Treatment
When the gum boil is linked to an infection inside a tooth, root canal treatment may be considered to remove the infected pulp and preserve the tooth where possible.
Learn MoreManagement of Dental Abscess
Coordinated care for the underlying abscess — combining drainage, treatment of the source, and appropriate aftercare — addresses the infection that has caused the boil.
Learn MoreGum Disease Treatment
Where the boil arises from periodontal infection, targeted cleaning of gum pockets and ongoing gum care is directed at resolving the underlying gum condition.
Learn MoreTooth Extraction
In some situations — particularly where a tooth cannot be saved — extraction may be recommended to fully resolve the infection and protect surrounding structures.
Learn MoreYour First Step
Importance of Professional Dental Assessment
A gum boil is almost always a signal that something beneath the surface requires attention. Even when the lesion is painless or small, it typically indicates an ongoing process — usually infection — that will not resolve without targeted care. Professional examination allows the underlying cause to be identified so that treatment can address the source rather than just the symptom.
During your assessment, your dentist will examine the area carefully, review your dental and medical history, and often take X-rays to check for signs of infection at the root of a tooth, bone loss or other contributing factors. This helps distinguish between boils arising from within a tooth, those linked to gum disease and less common causes.
Once the source is identified, a personalised treatment plan can be developed — which may combine drainage, root canal treatment, management of dental abscess, periodontal care or, where necessary, extraction. Early assessment may reduce the risk of complications and offer a wider range of options for managing the condition.
What to Expect
- 1Thorough examination of the gum boil and surrounding gum, teeth and soft tissues
- 2Review of symptoms, medical history and any previous dental treatment in the area
- 3X-rays where appropriate to identify root infection, bone involvement or hidden decay
- 4Clear explanation of the likely cause and the treatment options available
- 5Prompt emergency care where required to relieve symptoms and begin management
- 6Personalised treatment plan with follow-up to monitor healing and resolution
Two Convenient Locations
Visit Us in Central London
Assessment and treatment planning for gum boils and other dental concerns are available at our London clinic, where professional evaluation can help determine appropriate care options.
South Kensington
Now Open20 Old Brompton Road, South Kensington, London SW7 3DL
Mon & Wed: 9 am – 6 pm
Tue & Thu: 9 am – 8 pm
Fri: 9 am – 5 pm
Sat & Sun: 10 am – 4 pm
1 min from South Kensington tube (District, Circle & Piccadilly)
City of London
Opening May 20265 Ave Maria Lane, City of London, London EC4M 7AQ
Mon – Fri: 8 am – 8 pm
Sat & Sun: Closed
3 min from St Paul's tube (Central line) · 5 min from Blackfriars
Common Questions
Gum Boil FAQ
Your Dental Team
Experienced Dentists
All our dentists are GDC registered and experienced in diagnosing and managing dental infections, including gum boils and associated abscesses, providing prompt and personalised care.
Dr. Yasha Y Shirazi
Principal Dentist & Clinical Director
GDC: 195843
Dr. Reza Davari
Dentist
GDC: 302422
Dr. Kamran Yazdi
Dentist
GDC: 197926
Dr. Andreia Phipps
Dentist
GDC: 229601
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Your Safety Is Our Priority
Our South Kensington clinic is regulated by the Care Quality Commission (CQC) and all our clinicians are registered with the General Dental Council (GDC).
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Assessment for Gum Boil
Noticed a Lump on Your Gum?
If you notice a lump or swelling on your gum that may indicate a gum boil, a professional dental assessment can help identify the cause and determine appropriate treatment options based on your individual needs.
