Noticing a darkening of a child’s gums prompts concern about their oral health. The color of healthy gum tissue typically ranges from a uniform pale pink to shades of brown, depending on an individual’s genetic background. Darkening or black spots on the gums can be caused by a wide range of factors, most of which are harmless and temporary, while a few signal underlying health issues. Understanding the difference between normal variation and causes that require medical attention can help parents respond appropriately.
Physiological and Developmental Reasons
The most common reason for a child’s gums to appear dark is entirely physiological, stemming from the natural presence of melanin. Melanin is the pigment responsible for the color of skin, hair, and eyes, and its concentration in the oral tissues is determined by genetics and ethnicity. Children with darker skin tones often have a higher level of melanin, which results in diffuse, harmless hyperpigmentation of the gingiva, making the gums appear dark brown or black.
This type of pigmentation is a normal variation and has no association with disease or poor health. If the dark color has always been present and is uniform across the gum tissue, it is a benign, inherited trait that requires no treatment.
Another common cause of localized dark spots, particularly in infants and young children, is an eruption hematoma, sometimes called an eruption cyst. This phenomenon occurs when a tooth, whether a baby tooth or permanent tooth, is preparing to break through the gum line. A fluid-filled sac forms over the erupting tooth, and if blood mixes into this fluid, the area takes on a dark blue or black, bruised appearance.
Eruption hematomas are temporary consequences of teething and typically resolve once the tooth successfully emerges. They may be caused by minor trauma or impact to the gum in the area where the tooth is developing. Unless the swelling causes significant pain or the tooth fails to erupt after a prolonged period, this dark spot is considered a temporary and harmless developmental occurrence.
External Factors and Medications
Dark spots or discoloration on a child’s gums can also be the result of direct external contact or the ingestion of certain substances. Physical trauma is a frequent cause, as gum tissue is susceptible to bruising. A fall, a blow to the mouth, or even accidentally biting down hard on a sharp object can damage the underlying blood vessels, leading to a localized hematoma that appears dark purple or black.
This bruising is temporary and will fade as the body naturally reabsorbs the blood, typically within a few days or weeks. Parents might also observe localized darkening due to poor oral hygiene practices, where heavy buildup of plaque and tartar near the gumline can give the illusion of darker gums. In rare cases, a dead or infected tooth can cause the surrounding gum tissue to take on a dark appearance due to tissue necrosis or internal staining.
Specific medications can also induce a temporary, extrinsic discoloration of the oral tissues. Iron supplements, which are often prescribed to children with anemia, can cause black or dark brown staining on the teeth and sometimes the adjacent gum tissue. This staining results from a chemical reaction between the iron and sulfur in the mouth.
The discoloration caused by iron supplements is harmless and not a sign of toxicity. While the stain on the teeth may require professional cleaning to remove, the gum discoloration usually resolves once the medication is stopped or if the child’s oral hygiene is improved. Certain antibiotics, such as minocycline, are also known to cause pigmentation in oral tissues, though this is a less common side effect in children.
Potential Underlying Health Concerns
While most causes are benign, a few rare systemic or congenital conditions can manifest with dark gum pigmentation. One such rare condition is Peutz-Jeghers syndrome (PJS), a genetic disorder that predisposes individuals to the development of gastrointestinal polyps and an increased risk of cancer. The condition is characterized by small, dark brown or black spots, known as mucocutaneous pigmentations, which appear on the lips, around the mouth, and on the oral mucosa, including the gums.
These spots are typically freckle-like macules, not plaques, and their presence in childhood can be an early indicator of the syndrome. Children with PJS usually also have pigmentation on their hands and feet, and they may experience symptoms like recurrent abdominal pain or intestinal bleeding due to the polyps. The pigmentations themselves are harmless, but they signal the need for diagnostic evaluation of the gastrointestinal tract.
Another systemic cause is Addison’s disease, a rare disorder where the adrenal glands do not produce enough hormones. A common symptom is the hyperpigmentation of the skin and mucous membranes, which can include the gums, lips, and inner cheeks. The darkening results from high levels of adrenocorticotropic hormone (ACTH), which stimulates the pigment-producing cells.
Darkening of the gums, which can be patchy or diffuse, often precedes other symptoms of Addison’s disease, such as chronic fatigue, low blood pressure, and unexplained weight loss. The presence of unexplained, diffuse oral pigmentation in conjunction with these systemic symptoms warrants immediate medical investigation. In very rare instances, heavy metal exposure, such as lead, can cause a dark line on the gums, but this is usually accompanied by other signs of systemic toxicity.
When to Seek Professional Consultation
Parents should seek professional consultation with a pediatric dentist or pediatrician when the gum discoloration is a new development or is accompanied by other physical symptoms. Any sudden change in the color of the gums, particularly if the dark area appears to be spreading or is a new, isolated spot, should be evaluated. A professional can distinguish between benign ethnic pigmentation and a pathology.
Immediate attention is warranted if the dark gums are accompanied by signs of infection or discomfort. These symptoms could indicate a localized issue like an abscess or a more severe infection like necrotizing ulcerative gingivitis. Red flags requiring evaluation include:
- Pain
- Bleeding
- Swelling
- A persistent bad odor
- Fever or lethargy
If the discoloration is accompanied by other systemic concerns, such as unexplained weight loss, persistent abdominal pain, or changes in energy levels, a consultation with a pediatrician is necessary. These broader symptoms, in combination with oral pigmentation, can point toward one of the rare underlying conditions. If the discoloration is suspected to be from a medication, consulting the prescribing doctor is appropriate to discuss alternatives or management strategies.