We know that the lips are made of skin which is soft and delicate. As a result of this, they can easily crack and split under certain conditions. This can be painful and you can bleed, but the peeling lips usually do not indicate a serious problem. This condition can be bothersome, so it is very important to understand the cause of peeling lips and the ways in which the healing can be promoted.
The most common symptoms of peeling lips include:
The split or peeling lump can develop gradually, so it can be difficult to pinpoint the exact cause of it. This condition can be bothersome so it is very important to know what the cause of it is and how to promote the healing process. Here are the most common causes of peeling lips:
- Allergy: The allergic reaction to toothpaste, lipstick, moisturizer and any item applied to or around your lips can lead to a split up. There can be other symptoms, such as itching, irritation, severe dryness or an acute eczema – like rash on the lips. If you have noticed that your lips are peeling after using a new lip product, then you should stop using it and see if this condition improves. If the problem which is causing allergy is not identified or corrected, then this condition can become ongoing so you should talk with your doctor. 
- Vitamin and mineral deficiency: Vitamin B includes riboflavin, folic acid, biotin, niacin and thiamine. Vitamin B is water – soluble vitamin which is playing a role in the metabolism, helps your body to fight against diseases and provides energy. The Vitamin B contributes to a healthy skin, so a deficiency in it can lead to many health problems, such as rashes, dryness, split lips and acne. The low levels of iron and zinc can also lead to peeling lips, especially at the corners of the mouth. 
- Dehydration: There are some cases when the peeling lips can be caused by an underlying problem, such as dehydration. This is happening when your body does not have enough amount of fluid. Also, you can become dehydrated from illness, intense sweating, diarrhea and vomiting. Also, there is a risk for dehydration if you do not take enough fluids. It is known that the dehydration makes harder for your body to function properly. The severe dehydration can be life – threatening condition.
- Lip injury: The peeling lips can happen after an injury. This is including a blow to the mouth, falling and hitting your mouth, getting a paper cut or biting your lip. In addition to peeling lips, you can experience swelling and bleeding.
- Sun damage: We are using sunscreen to protect the skin from the harmful UV rays, but it is important to protect our lips as well. When we are exposing our lips to the sun, then this could lead to inflammation. The long – term exposure can cause the lips to become stiff and dry which will result in splitting or cracking. 
- Chapped lips: We know that the chapped lips are form of inflammation which is triggered by skin irritation. Our lips can become extremely dry and cracked any time of the year due to environmental factors, such as wind exposure, dry air and cold weather. It is known that the angular cheilitis is affecting the corners of the mouth and it can be due to environmental factors and a host of other causes. We know that our lips are prone to dryness, splitting, peeling and flaking because they do not have the same protection from the elements as other skin. Also, lips are not able to produce their own moisture. 
Every single person can get peeling lips, particularly if they have dry skin. Also, taking certain medications can increase your risk of developing peeling lips. The most common medications and supplements which can cause peeling lips include:
- Chemotherapy drugs 
- Retinoids 
- Vitamin A
It is noticed that people who have dehydration or who are malnourished are having higher chances of getting peeling lips compared to other people.  If you have some of the mentioned conditions, then you should talk with your doctor, so you can start with the treatment of peeling lips.
 Fonseca A, Jacob SE, Sindle A. Art of prevention: Practical interventions in lip-licking dermatitis. International Journal of Women’s Dermatology. 2020;6(5):377-80.
 NHS. Thiamine (vitamin B1). Retrieved from www.nhs.uk/medicines/thiamine-vitamin-b1/
 Hennessy BJ. Lips and sun damage. Mouth and Dental Disorders. Retrieved from www.msdmanuals.com/home/mouth-and-dental-disorders/lip-and-tongue-disorders/lips-and-sun-damage
 Shulman JD, Lewis DL, Carpenter WM. The prevalence of chapped lips during an army hot weather exercise. Military Medicine. 1997;162(12);817-9.
 Santos PSdS, Tinoco-Araujo JE, de Souza LMdV, et al. Efficacy of HPA Lanolin® in treatment of lip alterations related to chemotherapy. Journal of Applied Oral Science. 2013;21(2):163–6. doi:10.1590/1678-7757201302308
 Madke B, Shah H, Singh A, et al. Oral retinoid-induced cheilitis. Indian Journal of Drugs in Dermatology. 2016;2(1):50. doi:10.4103/2455-3972.184104
 Sheetal A, Hiremath VK, Patil AG, et al. Malnutrition and its oral outcome – A review. Journal of Clinical and Diagnostic Research. 2013;7(1):178–80. doi:10.7860/JCDR/2012/5104.2702