Finding an unexpected red spot on the lip is a common discovery that prompts an immediate online search. Most of these spots are not a cause for serious concern, but their appearance varies widely, ranging from a temporary injury to a stable dermatological finding. Understanding the spot’s characteristics—such as its duration, pain level, or changes over time—is the first step in identifying its likely cause. The source of the redness generally falls into categories related to minor trauma, blood vessel changes, or active infection and inflammation.
Temporary Red Spots from Injury or Irritation
Many red spots on the lip are transient reactions to physical factors or minor trauma. The delicate lip tissue is susceptible to injuries, such as biting or rough brushing, which can lead to a small bruise or a tiny burst blood vessel, known as a petechial hemorrhage. These small bleeds appear as a red or purplish spot and usually resolve completely within a few days as the body reabsorbs the blood.
Other red spots result from contact with an irritating substance, leading to a localized inflammatory reaction called contact cheilitis. Common culprits include ingredients in lip balms, lipsticks, or toothpastes, especially flavorings like cinnamon or mint, which can cause the lip to become red, dry, and scaly. Highly acidic foods, like citrus fruits, can also cause temporary irritation. This inflammatory response usually fades once the offending product is avoided.
Post-inflammatory hyperpigmentation (PIH) can follow any significant lip irritation or injury, such as a severe cold sore or chapping. Although PIH typically manifests as brown or darker discoloration, the initial healing stage is marked by intense redness. This redness is a sign of inflammation and will gradually lighten as the skin repairs itself.
Persistent Benign Vascular Lesions
Some red or purple dots are permanent features related to localized changes in small blood vessels. These lesions are benign, meaning they are harmless, and they do not resolve on their own.
One of the most common persistent red-to-purple spots is a venous lake, formally known as a phlebectasis. This is a soft, compressible, dark blue or purplish bump that forms when a small, superficial vein becomes dilated. Venous lakes are most frequently found on the lower lip of older adults and are associated with chronic sun exposure.
Another stable vascular growth is a cherry angioma, which appears as a small, bright ruby-red papule. This spot is a cluster of tiny blood vessels that form a benign tumor, often presenting as a slightly raised dome on the lip surface. Unlike spots from injury, these vascular lesions maintain their stable size and color unless traumatized.
Fordyce spots, which are enlarged sebaceous (oil) glands, are typically white or yellow, but they can occasionally appear pale red if inflamed or located at the vermillion border. These are not related to blood vessels but represent a normal anatomical variant. They are small, painless bumps that can appear in clusters and are permanent.
Red Dots Caused by Infection or Inflammation
Red spots that are painful, accompanied by swelling, or have a cyclical pattern often point toward an infectious or inflammatory process. The most recognizable cause is the Herpes Simplex Virus (HSV), which causes cold sores. The initial stage presents as a small, tingling, painful red bump before progressing into fluid-filled blisters that eventually crust over.
A red spot can also be part of a broader inflammatory condition, such as allergic contact dermatitis. Here, the redness is often accompanied by swelling, itching, and sometimes a feeling of burning. This reaction is a delayed hypersensitivity response to an allergen, such as a new cosmetic product or dental material. The inflammation can be dynamic, sometimes spreading across the lip or surrounding skin.
Angular cheilitis causes redness and cracking specifically at the corners of the mouth, often due to an overgrowth of yeast or bacteria. This is typically triggered by chronic moisture accumulation, such as from lip licking or ill-fitting dentures. The redness is persistent and usually accompanied by discomfort or pain upon opening the mouth.
When to See a Dermatologist
While most red spots on the lip are harmless, certain features indicate a need for professional medical evaluation to rule out more serious conditions. Any red spot that persists for longer than two to three weeks without showing signs of healing or fading should be examined by a dermatologist. This persistence suggests the spot is not a temporary injury or inflammation.
It is important to seek prompt attention if a spot exhibits rapid changes in its appearance, such as quickly increasing in size, suddenly changing color, or developing irregular borders. Bleeding from the spot without any preceding injury is another concerning sign. Additionally, any spot that feels hard or firm when touched warrants a professional diagnosis. These warning signs are important because, although rare, they can be associated with precancerous lesions like actinic cheilitis or certain forms of skin cancer.