Color Changes and Spots in the Mouth

ByBernard J. Hennessy, DDS, Texas A&M University, College of Dentistry
Reviewed/Revised Jan 2024

    Color changes in the mouth may be caused by

    • Bodywide (systemic) disease

    • Mouth conditions

    Bodywide diseases that can cause color changes in the mouth include the following:

    • Anemia (low blood count) may cause the lining of the mouth to be pale instead of the normal healthy reddish pink.

    • Measles, a viral disease, can cause spots to form inside the cheeks. These spots, called Koplik spots, resemble tiny grains of grayish white sand surrounded by a red ring.

    • Addison disease and certain cancers (such as malignant melanoma) can cause dark color changes.

    • In a person with AIDS, purplish patches caused by Kaposi sarcoma may appear on the palate.

    • Small red spots (called petechiae) on the palate (roof of the mouth) can be a sign of a blood disorder or infectious mononucleosis.

    Mouth conditions that cause color change may or may not represent a problem. For example, white areas can appear anywhere in the mouth and often are simply food debris that can be wiped away. White areas may also be caused by cheek biting or by rubbing the cheeks or tongue on a sharp part of a tooth or dental filling. Various conditions may cause white areas (such as a yeast infection [candidiasis]), thick white folds (a hereditary condition called white sponge nevus), a white line running along the inside of the cheek opposite the teeth (linea alba), or a grayish white area of the inside lining of the cheek (leukoedema).

    Persistent white areas should always be evaluated by a dentist or doctor because they may be an early sign of mouth cancer. Persistent red areas (called erythroplakia) may also be a sign of mouth cancer.

    Examples of color changes in the mouth include the following:

    • The mouth may have dark blue or black areas due to silver amalgam from a dental filling, graphite from falling with a pencil in the mouth, or a mole.

    • Heavy cigarette smoking can lead to dark brown or black discoloration (usually of the gums) called smoker’s melanosis.

    • Brown areas in the mouth can be hereditary. For example, darkly pigmented areas are particularly common among dark-skinned and Mediterranean people.

    • Food pigments, aging, and smoking may cause teeth to darken or yellow.

    Drugs Mentioned In This Article
    Test your KnowledgeTake a Quiz!
    Download the free Merck Manual App iOS ANDROID
    Download the free Merck Manual App iOS ANDROID
    Download the free Merck Manual App iOS ANDROID