The condition of cracked corners of the mouth is common, formally known as Angular Cheilitis (AC). This inflammatory process affects the angles where the upper and lower lips meet. While AC can be stubborn, it is usually manageable once the underlying factors are correctly identified. Understanding the specific appearance and causes is the first step toward effective relief and prevention.
Identifying Angular Cheilitis
Angular cheilitis presents as red, swollen patches or roughly triangular lesions specifically at the mouth corners. Primary signs include redness, skin breakdown, cracking, and fissuring. These painful cracks often worsen when the mouth is opened, making eating or talking difficult.
The affected area may also show signs of scaling, crusting, or oozing, indicating an inflammatory response. Unlike generalized dry or chapped lips, AC is localized to the commissures and may be bilateral or unilateral. It is distinct from a cold sore (herpes labialis), which is caused by a virus and typically involves the lip border rather than just the corner.
The Root Causes of Cracked Lip Corners
Angular cheilitis is considered a multifactorial disorder, meaning it results from a combination of local and systemic predisposing factors. The core mechanism is the retention of moisture at the lip corners, which leads to maceration—the softening and breakdown of the skin barrier. This compromised skin then becomes vulnerable to secondary infection or inflammation.
Mechanical and Behavioral Factors
Saliva pooling frequently triggers the initial breakdown of the skin. Habits such as chronic lip licking or thumb-sucking constantly moisten the area, and as the saliva evaporates, it leaves the skin drier, prompting more licking in a vicious cycle. Anatomical issues, such as ill-fitting dentures, a loss of vertical dimension (the space between the upper and lower jaw), or deep skin folds, can create creases where saliva collects. This sustained moisture provides an ideal, warm environment for opportunistic microorganisms to thrive.
Infectious Factors
The majority of angular cheilitis cases involve a secondary infection, most commonly by the fungus Candida albicans (yeast). This yeast is normally present in the mouth but can overgrow when the skin barrier is damaged by constant moisture. Bacterial infections, primarily Staphylococcus aureus, are also frequently detected, often alongside Candida, resulting in a polymicrobial infection.
Nutritional and Systemic Factors
Nutritional deficiencies can predispose an individual to AC by compromising skin and immune health. Deficiencies in B vitamins (Riboflavin, Pyridoxine, and Cyanocobalamin) are implicated, as these nutrients are important for tissue repair. Iron deficiency, which can lead to anemia, is a known systemic factor. A lack of Zinc, crucial for immune function and wound healing, can also impair the body’s ability to maintain healthy skin at the mouth corners.
Immediate Self-Care and Home Remedies
Addressing the behavioral factors that contribute to moisture retention is the most immediate and effective form of self-care. It is important to stop the habit of licking the lips or the affected area, as this perpetuates the cycle of irritation and breakdown. Gently keeping the area dry after eating or drinking helps prevent saliva from pooling in the creases.
A primary goal of home treatment is to restore the skin barrier and protect the area from external irritants. Frequent application of a thick, protective emollient, such as unflavored petroleum jelly or zinc oxide ointment, creates a physical shield against moisture. Applying this barrier cream at night is particularly helpful, as drooling or mouth-breathing during sleep can significantly worsen the condition.
For localized inflammation without signs of a deep infection, a short course of an over-the-counter hydrocortisone 1% cream may reduce redness and swelling. Use this cautiously for no more than a few days, as topical steroids can thin the skin and are not effective against fungal or bacterial components. If the condition does not show significant improvement after 3 to 5 days of diligent barrier application and behavioral changes, it is unlikely to resolve with self-care alone.
Understanding Medical Treatment Options
If symptoms persist for more than 7 to 10 days despite consistent self-care, or if the pain and inflammation are severe, professional medical attention is necessary. A doctor or dentist will perform a clinical examination and may take a diagnostic swab to identify the specific microbe, such as Candida albicans or Staphylococcus aureus. Identifying the pathogen ensures the correct treatment is prescribed.
The standard medical approach targets the identified infectious agents. If a fungal infection is confirmed, a topical antifungal cream (e.g., clotrimazole or nystatin) is typically prescribed for two weeks. For cases involving a bacterial component, a topical antibiotic ointment, such as mupirocin, may be used. Often, a combination cream containing both an antifungal and a low-dose corticosteroid is used to simultaneously combat the yeast and reduce inflammation. If a systemic nutritional cause is suspected, a blood test may be ordered to check for deficiencies, and oral supplementation will be added to the treatment plan.