Two-toned lips refer to a difference in color between parts of the lips, where one area appears darker or lighter than another. This can manifest as the upper lip being a different shade from the lower lip, or as patches of discoloration. Variations in lip color are common and stem from numerous factors.
Common Environmental and Lifestyle Factors
Sun exposure is a common cause of uneven lip pigmentation. Ultraviolet (UV) radiation stimulates melanocytes, the cells that produce melanin, leading to hyperpigmentation. This can result in darker areas, especially on the vermillion border, as lips have fewer protective cellular layers than other skin areas.
Smoking impacts lip color due to chemicals in tobacco products. Nicotine constricts blood vessels, reducing blood flow and depriving the skin of oxygen and nutrients. This reduced circulation can cause melanin in the lips and gums to darken, leading to blotchy, purple, dark brown, or black discoloration. The repeated puckering motion while smoking also contributes to changes in lip appearance.
Chronic dryness and irritation contribute to two-toned lips. Repeated licking, biting, or picking at dry skin can cause inflammation. This inflammation can lead to darker blotches. Even aggressive makeup removal can cause low-grade inflammation and subsequent discoloration.
Diet and hydration play a role in lip health and appearance. Dehydration can cause lips to lose their natural moisture and color, making them appear pale and dry. Consuming sufficient fluids helps maintain healthy lip color and prevents dryness. Certain dietary habits, such as overconsumption of alcohol or caffeinated drinks, can also contribute to dehydration and lip discoloration.
Underlying Health Conditions
Hyperpigmentation disorders can cause uneven lip coloring. Melasma, sometimes called the “mask of pregnancy,” causes dark, irregular patches, often on the upper lip, cheeks, and forehead. This condition is linked to excessive melanin production, often triggered by hormonal changes like pregnancy or oral contraceptives, and exacerbated by sun exposure. Post-inflammatory hyperpigmentation can also arise from allergic reactions or skin trauma like burns.
Hypopigmentation conditions can result in lighter patches on the lips. Vitiligo, an autoimmune disorder, causes the immune system to attack melanocytes, leading to pigment loss. This results in white or light-colored patches on the lips, which may have irregular or darker borders. These depigmented areas can be more sensitive to sunburn.
Hormonal changes, beyond those associated with pregnancy, can influence lip pigmentation. Fluctuations throughout the menstrual cycle or with certain medications can contribute to hyperpigmentation. These hormonal shifts stimulate melanin production, affecting various areas of the body, including the lips. Increased levels of estrogen and progesterone are particularly involved in these changes.
Certain medications can cause lip discoloration as a side effect. Drugs such as cytotoxic agents used in cancer treatment, antipsychotics, anticonvulsants, antimalarials, and tetracyclines can lead to hyperpigmentation. Medications containing heavy metals may also induce gingival pigmentation that can extend to the lips. These drug-induced changes often result from stimulating melanocyte activity or depositing drug metabolites in the oral mucosa.
Nutritional deficiencies can impact lip health and color uniformity. A lack of B vitamins (B2, B3, B6, B9, B12), iron, and zinc can contribute to various lip issues, including changes in lip color and dryness. For instance, pale or gray lips can indicate iron deficiency anemia or a lack of vitamin B12, both of which affect red blood cell function and oxygen transport to tissues.
When to Seek Professional Advice
New or rapidly progressing lip discoloration warrants medical attention. If you observe a sudden change in lip color or if existing two-toned areas quickly expand, consulting a healthcare professional is advisable. This ensures any underlying issues are identified promptly.
Professional help is also important if the discoloration is accompanied by other symptoms. These can include pain, swelling, itching, bleeding, sores, or changes in lip texture. Such accompanying symptoms may indicate an infection, allergic reaction, or other medical conditions requiring diagnosis and treatment.
If you suspect an underlying medical condition is causing your two-toned lips, or if lifestyle adjustments have not improved their appearance, a doctor’s visit can provide clarity. While many causes are harmless, some discolorations can signal more serious health concerns. A healthcare professional can provide a proper diagnosis and discuss appropriate management options.