What is lupus ?

Lupus erythematosus is an autoimmune disease that can affect many organs and systems in the body, with several types of lupus existing. The word "lupus," which means wolf in Latin, comes from the skin rash it causes on the face (erythema) that resembles a wolf mask.

Women of childbearing age are more likely to be affected, and the diagnosis is based on several tests. Treatments include orally administered and topical medications, as well as lifestyle changes. Lupus can affect black skin differently from light skin, with specificities in skin manifestations and treatments. This review provides a comprehensive overview of lupus and its clinical management, highlighting differences between pigmented and light skin.

What are the different types of lupus ?

There are several types of lupus, including cutaneous lupus, discoid lupus, systemic lupus, neonatal lupus, and drug-induced lupus.

What is systemic lupus erythematosus (SLE)?

Systemic lupus is the most common type of lupus, which can affect multiple organs. The most common symptoms include fatigue, fever, joint pain, skin rashes, headaches, and blood clotting disorders, but symptoms can vary greatly from person to person. Some patients may have very mild symptoms or no symptoms for prolonged periods.

What is cutaneous lupus?

Cutaneous lupus is a type of lupus that mainly affects the skin and can cause skin rashes, red and scaly patches, painful sores, and permanent scars. Symptoms vary depending on the specific form of the disease. There are three main forms of cutaneous lupus: acute, subacute, and chronic, each with its own symptoms and locations. The acute form manifests as red, scaly rashes on sun-exposed areas, while the subacute form is characterized by red or pink lesions that do not heal. The chronic form is characterized by red, scaly, and raised patches on any part of the body.

What is discoid lupus?

A form of cutaneous lupus that presents as round, red plaques on the skin, which can cause scarring and hair loss. This form of lupus is mostly limited to the face.

What is drug-induced lupus?

A type of lupus caused by the intake of certain medications, such as immunosuppressive drugs, anticonvulsants, and antihypertensive drugs.

Can babies get lupus?

Yes, this is known as neonatal lupus. This type of lupus affects children born to a mother with lupus erythematosus, and those with neonatal lupus have excellent long-term outcomes when they only have skin lesions.

What causes lupus ?

Genetic abnormalities predispose the immune system to react abnormally, under the influence of internal and external factors (such as sun exposure). This reaction occurs when dead cells accumulate and immune cells react to their own antibodies, creating tissue inflammation. This activates cytokines (molecules produced by our immune system in response to infection or inflammation), which act as chemical messengers to set up autoimmune reaction loops.

How many people suffer from lupus worldwide?

The prevalence of systemic lupus erythematosus (SLE) varies considerably worldwide depending on several factors including ethnicity, age, sex, and other environmental and genetic factors. It is important to note that SLE is a complex disease and there is no single cause.

What are the dermatological manifestations of lupus?

Systemic lupus erythematosus is an autoimmune disease that can cause various types of skin problems. Lupus lesions are damage that occurs at the junction between the skin and the lower layer of the skin. Other types of skin problems that can occur in patients with systemic lupus erythematosus are vascular and non-vascular lesions. Vascular lesions can be caused by inflammation or obstruction of the blood vessels of the skin.

• Lupus lesions: Skin lupus lesions are common signs of systemic lupus erythematosus that affect the layer of skin called the dermo-epidermal junction. These lesions are caused by an attack of the immune system against healthy skin and can appear anywhere on the body in various forms such as red patches, bumps, blisters, or nodules. The lesions can be painful, irritating, and leave permanent scars. Prolonged exposure to sunlight and stress can exacerbate them.

• Vascular manifestations : Systemic lupus erythematosus can cause problems with blood vessels in the body. This can affect small vessels in the skin and internal organs, or larger vessels such as arteries and veins. The most common vascular manifestations are skin patches called livedo racemosa. These are caused by decreased blood flow in the blood vessels of the skin and can be a sign of vascular involvement in systemic lupus erythematosus. Other less common vascular manifestations may also occur, such as vasculitis, inflammation of blood vessels, and Raynaud's syndrome, which can cause a blue or white discoloration of the skin of the fingers and toes.

How is systemic lupus erythematosus diagnosed ? 

• Blood test: Early diagnosis of lupus is crucial in order to prevent tissue damage. Antibodies have been detected in the blood of lupus patients several years before diagnosis. Blood tests to detect autoantibodies are now available, but diagnosis is often delayed. Delayed diagnosis can lead to different outcomes for patients of different backgrounds. Patients with lupus often visit their doctor several times for symptoms before diagnosis.

• Artificial photoprovocation: Photosensitivity is a diagnostic criterion for systemic lupus erythematosus. Sun exposure can cause skin lesions and other manifestations of lupus. UVA and UVB rays applied artificially play an important role in the development of lupus. Skin lesions usually appear more than 48 hours after sun exposure and can be confirmed by a biopsy. Sun protection measures are important to prevent skin lesions in patients with lupus.

It is important to note that lupus is often diagnosed late in people with black skin due to difficulty recognizing signs and symptoms of the disease. Therefore, it is important for people with black skin to be informed about lupus symptoms and to consult a doctor if they experience signs such as skin rashes, joint pain, and fatigue.

Lupus erythematosus and black skin

The classic symptomatology on light skin is enriched in dark skin, where different skin manifestations can be observed. Visible signs on the skin (such as redness, spots or thickening) may be different from those observed in people with light skin. One can particularly observe a uniform loss of pigmentation called "achromic depigmentation," which can resemble a skin disease called "vitiligo." One can also see a significant increase in pigmentation due to degeneration of certain skin cells. Depending on the predominance of these different symptoms, the appearance of the disease may vary, but it is generally easy to diagnose.

Picture credit : getty images

Discoid lupus in black subjects

Discoid lupus is a chronic skin disease that is diagnosed based on a combination of clinical signs observed during examination, test results, and blood analyses. When looking at this disease in people with black skin, it can sometimes have a different appearance from that in people with light skin.

How is lupus treated ?

Lupus is a chronic condition in which the body attacks different parts of itself, such as the skin, joints, organs, and nervous system. Treatments depend on the severity of symptoms and the affected parts.

·         By oral administration :

Antimalarials are medications used to treat lupus, but they may have different side effects depending on the individual. In people with dark skin, taking these medications may increase the risk of damage to the cells in the eye, called retinopathy. This may be due to a genetic predisposition to retinal pigmentation disorders. That is why it is important for patients to have regular eye exams and work with their doctor to find the best treatment.

 ·         Topical treatments :

Given the significant impact on daily life (joint pain, stress, fatigue, etc.), psychological support may be desirable. The chronic nature of the disease and uncertainty about its progression also cause anxiety. In addition, long-term corticosteroid use can lead to Cushing's syndrome in some individuals, with a distorted face and marked weight gain.

What are the complications of lupus erythematosus ? 

Squamous cell carcinoma is a type of skin cancer that develops in the squamous epithelial cells of the skin. Exposure to sunlight and other forms of UV radiation can damage the DNA in skin cells, causing genetic mutations that can lead to the development of cancerous cells. Individuals with fair skin and increased sensitivity to sunlight are more likely to develop squamous cell carcinoma than those with dark skin.

Patients with lupus have a higher risk of developing squamous cell carcinoma, but lupus is not the only cause of this disease. Other risk factors include excessive sun exposure, smoking, viral infections, and certain chronic skin conditions. Although patients with lupus have a higher risk of developing this disease, the risk is not considered major.

Voluntary depigmentation and squamous cell carcinoma in dark-skinned individuals

In the population with dark skin, many people practice artificial depigmentation to lighten their skin. There is often concern whether this can cause skin cancers, but this has not been proven so far. A study was conducted on two women who used artificial depigmentation products for about 15 years and eventually developed a skin cancer called squamous cell carcinoma. This cancer was found on areas of their skin exposed to the sun. The reasons why this happens are the destruction of melanin, exposure to the sun, and immunosuppression induced by dermocorticoids. It is also possible that the depigmentation products themselves have a carcinogenic effect.

Voluntary depigmentation and lupus-like symptoms in individuals with dark skin

"Lupus-like" refers to skin symptoms that resemble those of lupus but do not meet the precise criteria for diagnosis.

There are studies suggesting that the use of a molecule called hydroquinone (used in some voluntary depigmentation practices) may increase the risk of developing lupus-like skin symptoms or even complete cutaneous lupus.

Skin rashes that resemble lupus and occur on the face are quite rare. They typically occur after a few months of using products containing hydroquinone and mainly appear on the cheeks, forehead, and other parts of the face. These rashes may look like circles and may resemble erythematosus lupus.

It is possible to experience itching, and microscopic analysis of the skin shows damage to the junction that may resemble lichen planus or lupus. However, when the use of hydroquinone is stopped, the lesions quickly disappear and may leave post-inflammatory pigmentation.

In conclusion

The importance of sun protection: Sun protection is essential to prevent lupus flares in people with this autoimmune disease. Sunlight can trigger skin inflammation in people with lupus, which can cause skin lesions and joint pain.

People with lupus should avoid direct sun exposure as much as possible, especially between 10 am and 4 pm when the sun's rays are strongest. They should also wear protective clothing such as broad-brimmed hats, long-sleeved shirts, and long pants. It is also recommended to use a broad-spectrum sunscreen with an SPF of at least 30, even on cloudy days.

It is important to note that sun protection is important not only for people with lupus but also for anyone with sun sensitivity or a history of skin cancer. By using appropriate sun protection, you can reduce your risk of developing skin problems and protect your long-term health.

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