Skin Manifestations of Autoimmune Disorders - Causes, Diagnosis, and Treatment

Introduction:

The human body has the ability to fight against external agents and prevent an infection or a disease. There are multiple levels of defense, such as innate and acquired immunity. The immune response is when the body recognizes an external stimulus and fights against it to protect the body. In some cases, the body fights against itself, leading to various systemic disorders. Some of these disorders may be skin-related, or the systemic illness may have a cutaneous manifestation or symptom.

What Is Autoimmunity?

In a healthy body, the white blood cells attack harmful external agents or cells; in some instances, the body attacks valuable cells. This condition is called autoimmunity. Joints, internal organs, and skin are the areas that are usually affected. Autoimmunity is an immune response against the self. T and B lymphocytes are typically involved. Antibodies that act against the self are called autoantibodies. Autoimmunity may result in tissue damage or disrupt normal bodily functions; in some cases, it may present without causing any disease.

Some examples of autoimmune diseases are:

• Multiple sclerosis (a condition where the outer covering of the nerve cells are destroyed by the body’s own cells).

• Graves disease (disorder in which thyroid hormones are produced in excess).

• Rheumatoid arthritis (disorder affecting the joints).

• Insulin-dependent diabetes (a condition in which the pancreas produces little or no insulin, often referrred as type 1 diabetes).

• Systemic lupus erythematosus (inflammatory condition affecting the skin, kidneys, blood, brain, and other organs).

Who Is Prone to Become Autoimmune?

Around 5 % of the population is affected by autoimmune disorders. Among these, women have a higher chance of developing the disorder than men. Individuals in higher socioeconomic conditions tend to present with the disease more. There is a strong familial correlation.

What Causes Autoimmune Diseases?

The exact cause of how an autoimmune disorder develops has not yet been fully understood. There are, however, certain factors that trigger it, such as:

• Genetic Conditions: Multiple genetic conditions may combine to cause the disease.

• Gender: Increased estrogen levels may be why women are affected more, and some genes on the Y chromosome may help suppress the disease in men.

• Infections: Some infections may mimic the self-antigen, causing the body to react.

• Medications: Certain antibiotics (such as Captopril and Vancomycin) may trigger autoimmune disorders such as pemphigus foliaceus and pemphigus vulgaris.

What Are the Autoimmune Disorders That Affect Skin?

Autoimmunity may cause skin diseases such as:

• Systemic sclerosis (hardening of the skin).

• Dermatomyositis.

• Psoriasis.

• Alopecia areata (patchy hair loss).

• Vitiligo (change in the color of the skin, usually observed in patches).

• Lichen sclerosus.

Psoriasis:

It is a chronic autoimmune disorder that presents with redness of the skin and irritation. The red patches on the skin are raised and may be flaky, dry, silver-white in appearance, and resembles scales. It can be inherited. The symptoms may be triggered by sun exposure, alcohol, stress, infections, or injuries. In addition, patients with already suppressed immunity may have higher chances of developing the disorder.

Dermatomyositis:

As the name suggests, it primarily affects muscles. It is often associated with polymyositis, an autoimmune disease that causes muscle weakness, stiffness, and soreness. The patients may have difficulty in breathing and swallowing. The skin manifestations include rash in the upper body and thickening and tightening of the skin. In addition, patients may have purple-colored eyelids. The condition is more common in women. In children, the symptoms include rash, fever, fatigue, and weakness, and it is found in children of age between 5 and 15.

Some common autoimmune blistering skin conditions include:

• Pemphigus.

• Epidermolysis bullosa acquisita.

• Pemphigoid.

• Dermatitis herpetiformis.

Pemphigus:

It is a disease that typically presents as blisters. This occurs when antibodies bind to the skin and disrupt the skin cells' structure. These antibodies disrupt keratinocyte- cells responsible for keratin production, and this disruption causes blisters. Pemphigus may be of different types, such as:

• Pemphigus Vulgaris: In this type, blisters are seen around and inside the mouth and on the skin.

• Pemphigus Foliaceus: Blisters are seen on the trunk, scalp, and face.

• Paraneoplastic Pemphigus: This may be associated with non-Hodgkin lymphoma or other malignant conditions with ulceration in the mouth and skin.

Pemphigoid: This occurs due to autoantibodies that attack the dermal-epidermal junction; therefore, the blisters are subepidermal-below the epidermis. It comprises bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid.

• Bullous Pemphigoid: It occurs when the cell-to-cell connection is affected, causing the gap between the keratinocytes, thereby causing blisters. It is characterized by blisters or large patches of erosions when the blister breaks. It is a chronic condition where the symptoms range in severity. In some cases, the irritation might be mild, while in severe cases, multiple blisters may break to form ulcers. It is found in the legs, arms, and trunk; sometimes, it forms in the mouth. Involvement in the mouth may cause bleeding gums. It usually affects the elderly, but it can occur in any age group, with an equal predilection for both genders.

• Mucous Membrane Pemphigoid: It occurs when there is a split in the epidermal-dermal junction. It may lead to scarring. It is characterized by blister formation and ulceration. It is seen in the eyes, mouth, and skin.

• Pemphigoid Gestationis: It is seen in pregnant women or shortly after birth. It starts as an itchy rash around the belly button and may spread to the entire surface. The rash may progress to a blister similar to that of bullous pemphigoid. The placenta is believed to be the site of autoimmunity in this condition.

Dermatitis Herpetiformis: It is a blistering condition seen in the knees, elbows, and buttocks. It is associated with coeliac disease. The blisters are sub-epidermal in position. The autoantibodies target epidermal transglutaminase enzymes. The condition may resolve if the patient follows a gluten-free diet.

Epidermolysis Bullosa Acquisita: It typically has blisters that may break and cause erosion of the skin. The antibodies are targeted against the collagen in the basal layer of the skin. It is a rare condition. However, minor traumas can give rise to fluid-filled blisters. The skin responds in an exaggerated manner; even gentle rubbing, friction, or a rise in temperature may cause blister formation. There are different types of epidermolysis bullosa, and only one of them is autoimmune in nature. The autoimmune variant can develop soon after birth, while the other forms do not appear until after age 50.

Bullous Systemic Lupus Erythematosus: It is the cutaneous manifestation of a patient with systemic lupus erythematosus. It is characterized by subepidermal blisters.

Scleroderma: Scleroderma is a systemic condition that affects the body's connective tissues. It can affect the skin, blood vessels, organs, and muscles—the localized skin lesion results in thickened skin patches.

There are two forms of scleroderma:

• Progressive systemic scleroderma or systemic scleroderma (SS): affects the lungs, esophagus, heart, kidneys, and intestine.

• CREST syndrome is named after the symptoms:

  • Calcinosis- calcium accumulation below the skin.

  • Raynaud phenomenon (blueness or redress of digits).

  • Esophageal irritation.

  • Sclerodactyly (thickening of the skin around digits).

  • Telangiectasia (web-like patterns in the skin due to dilated blood vessels).

In addition, scleroderma patients may experience shortness of breath, wheezing, weight loss, constipation or diarrhea, joint pain, burning, or itching. It affects women after the age of thirties and forties more. In addition, occupational exposure to polyvinyl chloride and silica dust may act as a risk factor for developing scleroderma.

Linear IgA Bullous Dermatosis: It is a rare condition where the blisters are arranged in rings. It may be induced by drugs like Vancomycin. The IgA gets deposited below the epidermis and may target the basal layer proteins or collagen fibers which results in the formation of blisters.

How to Diagnose?

• The primary diagnosis is by observing the clinical symptoms, and further tests should be done for confirmation.

• A blood test may be done to:

  1. Test for autoantibodies in the bloodstream.

  2. Inflammatory markers.

• A biopsy is done for confirmation of the disease; a biopsy may be required after narrowing down based on the clinical symptoms.

• Bacterial or viral infections may be confirmed from the swabs from ruptured blisters.

What Is the Treatment?

• The primary treatment option for an autoimmune disorder is immunosuppressants. However, treatment is based on specific symptoms.

• Pemphigus and pemphigoid are treated by systemic corticosteroids and other immunosuppressive agents.

• Dermatitis herpetiform is treated with Dapsone. A gluten-free diet also helps to relieve the symptoms.

• If the skin manifestations are due to systemic conditions, treating the primary cause will automatically treat the skin condition.

Conclusion:

Autoimmune disorders are conditions where the body attacks itself. This may, in turn, cause various systemic and skin conditions. Recognizing the disease and giving an adequate treatment can significantly reduce skin disorders and prevent scarring. The patient may feel dejected due to the skin condition. Although there may not be a definitive treatment, immunosuppressive agents can significantly improve the quality of life of the patient.