Angular Cheilitis: How did it occur?

Angular cheilitis, also known as perleche, is an inflammation of the corners of the mouth, with a prevalence estimated at 0.7% of the American population in 2023. Painful and somewhat alarming at first glance, it can have several causes.

• Contact dermatitis.

  Contact dermatitis is responsible for just over 20% of cases of angular cheilitis. This condition occurs following contact between the lips and a substance they cannot tolerate, which triggers an immune response in the body. The compounds most frequently responsible for atopic dermatitis on the lips are nickel in people wearing dental braces, food (flavours, preservatives...), toothpastes, mouthwashes, lip balms and chewing gums. A patch test carried out by a healthcare professional can confirm the allergy. Angular cheilitis due to contact dermatitis disappears after the allergen causing it is avoided.

• An infection.

  The majority of angular cheilitis cases are due to an infectious agent. The main culprit is the yeast Candida albicans, which is part of the normal flora of the mouth. However, when it breaches the superficial layer of the lips and invades the tissues of the lip corners, this microorganism triggers an inflammatory response. It can also pave the way for a bacterial infection, for example by staphylococcus or streptococcus. This happens frequently: Candida albicans is present in 93% of angular cheilitis cases, but is only described as the sole pathogen in 20 to 50% of cases. In addition to these germs, certain viruses can cause angular cheilitis, including the herpes simplex virus. It's worth noting that the proliferation of these pathogens is facilitated by poor dental hygiene or certain diseases.

• The Sjögren's Syndrome.

  Angular cheilitis is the most common oral lesion in Sjögren's syndrome, according to a systematic study conducted with data from 2,426 patients affected by this disease, with an occurrence rate of 20 to 40%. Sjögren's syndrome is a rheumatological disease characterised by a dry mouth, also known as xerostomia, and a decrease in salivation, also referred to as hyposalivation. It results from lymphocytic infiltration and the destruction of the salivary glands. The drying of the mouth and lips caused by Sjögren's syndrome can lead to chapped lips, or even angular cheilitis.

• Exposure to cold or dry air.

  Extended exposure to cold and dry air, typical of winter, can weaken the lips and promote the onset of angular cheilitis. Indeed, cold and dry air reduces the hydration levels of the lips, making them more vulnerable to external aggressions. Cracks can then form on their surface, providing an entry point for the pathogens responsible for angular cheilitis.

• Some behaviours.

  Certain daily habits are also likely to cause angular cheilitis. Notably, this includes the licking of lips, a common reflex in response to feelings of dryness. Even though it seems to moisturise the lips, this action actually contributes to their dryness. Indeed, saliva contains enzymes, such as lipase, whose role is to break down food. When repeatedly applied to the corners of the mouth, it can weaken the skin barrier and pave the way for the proliferation of microorganisms, thereby increasing the risk of angular cheilitis.

  Tip : Instead of licking your lips to moisten them, it is better to apply a lip balm. By forming a protective layer on the surface of the lips, this treatment prevents the risk of dehydration and the entry of pathogens.

• The intake of certain medications.

  Some treatments, particularly those aimed at combating acne or certain inflammatory conditions, can promote the onset of angular cheilitis by weakening the skin of the lips. Acne treatments, such as isotretinoin, drastically reduce sebum production, leading to a generalised dryness of the skin and mucous membranes, including those of the lips. This dryness can cause cracks at the corners of the mouth, making these areas vulnerable to pathogens.

  Similarly, corticosteroids, often prescribed for conditions such as eczema, are valued for their potent anti-inflammatory properties. However, their use can weaken the local immune defences of the skin. By reducing the thickness of the epidermis, they create a favourable environment for the proliferation of microorganisms. Therefore, their prolonged use can contribute to the onset of angular cheilitis.

  Advice : It is recommended for individuals undergoing these treatments to pay special attention to the hydration and protection of their lips in order to limit the risk of angular cheilitis.

• Natural ageing.

  Ageing is a significant factor in the development of angular cheilitis. As we age, the oral commissure, also known as the marionette line, tends to deepen due to facial volume loss. This reduction in facial volume is exacerbated by other phenomena, such as gum recession or tooth extraction, which alter the structure and balance of the surrounding tissues. When the oral commissure deepens, it can become a receptacle for saliva, thus creating an area conducive to maceration. This constant moisture weakens the corners of the mouth, leading to irritation and increasing the skin's vulnerability to infections, particularly angular cheilitis. Therefore, although this condition can occur at any age, it is more commonly observed in older individuals.