Angular cheilitis and lupus rash are distinct skin issues with noticeable differences. While lupus can cause rashes on various parts of the body, it rarely affects the lips. On the other hand, angular cheilitis is an inflammatory skin condition that commonly leads to cracked and irritated corners of the mouth.

Lupus is an autoimmune disease, which means that the body’s immune system mistakenly attacks its own tissues or organs. Both systemic lupus erythematosus (SLE) — the most common type of lupus — and cutaneous lupus erythematosus (CLE) — lupus affecting only the skin— can cause rash.

People with lupus often experience angular cheilitis, a condition caused by a yeast infection linked to the long-term use of oral corticosteroids (steroids) prescribed for lupus treatment. After having angular cheilitis once, there’s a high chance, up to 80 percent, that it may happen again.

Keep reading to find out some key differences between these two common skin issues associated with lupus.

1. How They’re Diagnosed

Lupus is a systemic disease, which means that it can affect the entire body. Angular cheilitis is a more focused issue that affects only the skin around the corners of the mouth.

To diagnose lupus rash, dermatologists and rheumatologists perform various tests, including blood tests and skin biopsies. During a biopsy, a doctor takes a small sample of skin tissue and examines it to identify skin conditions. To confirm the diagnosis, the doctor will check for signs of autoimmunity in your bloodwork, using the antinuclear antibody (ANA) test.

Angular cheilitis is mainly diagnosed by its appearance, which includes irritation, scaling, or bleeding on one or both corners of the mouth. Your doctor may run a blood test to look to check for deficiencies in nutrients like iron, B12, or folate. In addition, a swab of the affected skin can help determine if there’s a fungal, viral, or bacterial infection that needs treatment.

Several risk factors, such as age, Crohn’s disease, diabetes, smoking, and deficiencies in iron or vitamin B12, can contribute to angular cheilitis. If you have any of these issues, your doctor will have a better understanding of what might be causing your symptoms. In some cases, a dentist might be involved because dental problems or wearing dentures can cause angular cheilitis.

2. How They Respond to the Sun

Around 75 percent of people with lupus are photosensitive, meaning their skin reacts to sunlight. As a result, lupus rashes — like the malar rash (butterfly rash) — may appear or become worse after you’ve been in the sun. Exposure to the sun can also trigger discoid lupus erythematosus (DLE), a type of CLE. A long-term condition, DLE that causes disc-shaped skin lesions to appear on areas exposed to sunlight. In people with darker skin, the discoid lupus lesions may appear as darker patches.

Subacute lupus erythematosus (SCLE), another type of CLE, can also cause circular and sometimes scaly markings on the arms, chest, and back. While the butterfly rash tends to heal within a few weeks and doesn’t leave a scar, other lupus rashes can take months to heal and cause scarring. Repeated sun exposure can trigger the symptoms to come back.

Angular cheilitis isn’t triggered by sun exposure. Instead, it usually occurs when saliva pools in the corners of the mouth and leads to infections.

3. How They’re Treated

Lupus rashes are treated by controlling the main autoimmune disease causing them. Immunosuppressants and antimalarial medication are used to reduce inflammation from within and reduce flare-ups. Topical corticosteroids can help with skin symptoms, along with consistent sun protection. A topical medication is applied directly to the skin to reduce inflammation.

Treatment for angular cheilitis depends on the cause. Antifungal, antibacterial, or antiviral creams can clear up specific infections like Candida, Staphylococcus aureus, or herpes simplex. If you have a vitamin deficiency that’s causing cracked lips and skin around the mouth, supplements can help. As with lupus rash, steroid creams can offer quick relief for inflamed skin.

4. How They Affect Daily Life

MyLupusTeam members often ask how others experience different symptoms. “Has anyone developed angular cheilitis with SLE?” asked one member. “It’s almost like cold sores on both sides of the corners of your mouth, but it’s not. It’s like really dry inflammation and cracking spots on the corner of your lips.”

One member responded, “I went to my autoimmune specialist dermatologist, and he said it was common in lupus. I also get lupus mouth sores. My dentist says angular cheilitis takes a long time to heal if on immunosuppressants coupled with the mechanical use of opening and closing your mouth.”

Angular cheilitis mainly affects the mouth and can be influenced by factors like diet, cosmetics, or lip balms. On the other hand, lupus rash may affect your outdoor activities, clothing choices, and sleep quality.

Both angular cheilitis and lupus rashes and sores can be physically uncomfortable and mentally taxing. You may worry that others will mistakenly assume you have a contagious skin condition or poor oral hygiene. Fortunately, with the right diagnosis, your health care team can help you find the best treatment options.

Talk With Others Who Understand

MyLupusTeam is the social network for people with lupus and their loved ones. On MyLupusTeam, more than 223,000 people with lupus come together to ask questions, give advice, and share their stories.

Do you get oral ulcers, crusted lips, and dryness, or other oral manifestations of lupus? Have you ever been diagnosed with angular cheilitis? Post your thoughts in the comments below, or start a conversation by sharing on your Activities page.