What is autoimmunity?
Almost all of the diseases in this category are thought to be diseases in which the immune system is not working properly. The immune system is a normal part of the body that is designed to protect us from infections with germs and viruses from the environment. Our immune system also helps us ward off cancer cell development in our bodies.
When the immune system gets out of control and starts attacking our own bodily tissues, it is called autoimmunity. In this situation, blood proteins called autoantibodies are produced that bind to and injure our own bodily tissues. Rheumatic diseases such as rheumatoid arthritis, lupus, dermatomyositis, and scleroderma are thought to be autoimmune diseases.
What are the typical skin symptoms of autoimmune diseases?
Subacute cutaneous lupus erythematosus (SCLE)
Subacute cutaneous lupus erythematosus (SCLE) is a form of lupus skin disease that is made worse by exposure to sunlight or artificial sources of ultraviolet radiation and does not produce scarring. It produces scaly red patches on the skin that can simulate the appearance of psoriasis occurring in sun-exposed areas of the body.
Patients with this form of skin lupus have a somewhat higher risk for developing the more severe internal complications of systemic lupus erythematosus compared to another common form of lupus skin disease named discoid lupus erythematosus.
Discoid lupus erythematosus (DLE)
Discoid lupus erythematosus (also referred to as DLE) produces scaly coin-shaped lesions most commonly occurring on the face or scalp, although other parts of the body can be affected. This type of skin lupus often produces scarring of the skin and hair loss that can be permanent. In addition, discoid lupus skin lesions often produce darkening and/or lightening of the skin color. When lupus shows itself initially only as discoid lupus skin lesions, such patients are at very low risk for later developing serious internal problems from systemic lupus.
Neonatal lupus
Neonatal lupus is a condition in which newborn babies develop skin lesions often simulating the appearance of subacute cutaneous lupus erythematosus. However, this occurs only when the mother of the newborn baby also had an immunological abnormality during pregnancy that resulted in her body producing Ro autoantibodies. It is thought that the mother's Ro autoantibodies cross over into the baby's blood circulation while still in the womb. These autoantibodies appear to be actually causing the skin lesions that occur after the baby is born and exposed to sunlight and other forms of ultraviolet light.
Complications of neonatal lupus
Normally neonatal lupus erythematosus (NLE) is a mild condition and the skin lesions go away on their own as the child gets older when the autoantibodies from the mother's blood disappear from the baby's blood. However, there is another complication that can occur in this setting and that is congenital heart block. Rather than developing skin lesions after delivery, babies develop damage in the conduction system in their hearts while still in the womb. This can be a very severe complication requiring permanent pacemaker placement in the heart of the baby.
Sjogren’s syndrome
The third condition I mentioned that is associated with Ro antibodies is Sjogren's syndrome. This is a condition that produces dryness in the eyes and mouth, most commonly in adult women. This dryness results from autoimmune damage to the glands that make tears and saliva. This is one of the most common of all rheumatic or arthritis-associated diseases but among the most difficult to diagnose–it is very often not diagnosed until it is quite advanced.
Patients who have Sjogren's syndrome also experience body tenderness and lethargy that can simulate conditions such as fibromyalgia. In addition, internal organ damage can occur in Sjogren's, such as kidney problems, nerve injury, and blood vessel injury.
What are the blood tests for autoimmune diseases?
There are some blood tests one can do that can reflect how active the immunological disease is inside our bodies in diseases like rheumatoid arthritis, lupus, and scleroderma. These tests are routinely ordered by doctors who are treating such patients. This information can be very helpful at times both in the diagnosis of the specific problem and in guiding treatment of the problems over time.
Rheumatoid factor
In a disease like rheumatoid arthritis, the most common blood test abnormalities are the presence of rheumatoid factor. Rheumatoid factor is a type of autoantibody present in the blood of almost all patients with rheumatoid arthritis who have the really destructive form of the disease.
This particular test also indicates a risk for some of the complications that can occur in rheumatoid arthritis, in parts of the body outside of the joints. A test like the rheumatoid factor certainly can be helpful in making the initial diagnosis of rheumatoid arthritis. In addition, the amount of rheumatoid factor in the blood can be an indication of the state of activity of the immunological illness inside the body.
Antinuclear antibody assay (ANA)
Another test is the antinuclear antibody assay (the "ANA test" for short). The ANA test is almost always positive in rheumatic diseases such as lupus. In addition, it is often positive in rheumatoid arthritis, dermatomyositis, and scleroderma.
This test, since it can be positive in a number of these diseases, is not diagnostic of any one particular disease. A physician will use the ANA test to screen for this general group of illnesses, and if that is positive, then will do more specific tests to make a specific diagnosis such as lupus.
However, one thing that must be kept in mind in interpreting the results of the ANA test is that it can also be positive in other disease settings that are not related to arthritis. Even normal individuals, on occasion, will have abnormal ANA test results. This occurs even more frequently in older, healthy individuals. Certain medications can trigger a positive ANA test. The point is that the physician must be very careful in interpreting the results of the ANA test and should counsel patients about the true meaning of an ANA test result. I see a lot of confusion produced as a result of physicians in the community not being fully aware of the various pluses and minuses of the ANA test.
Antibody to neutrophil cytoplasmic antigens (ANCA)
I will mention one other laboratory test in this context. That is the ANCA test. ANCA stands for "antibody to neutrophil cytoplasmic antigens." This test is often positive in forms of blood vessel inflammation such as vasculitis.
One of the strongest disease associations of the ANCA test is a disease called Wegener's granulomatosis. This is a disease that can attack blood vessels in different parts of the body, including the skin. Recognizing the characteristic patterns of skin changes can be a clue to the diagnosis of this disease and getting patients on proper treatment for the internal complications that can be very severe (lung and kidney injury).
However, like the ANA test, one must be careful in interpreting the ANCA test results. The ANCA test can be positive in other conditions besides vasculitic illnesses, such as Wegener's granulomatosis.
The treatment really has to be individualized to the specific disease and to the specific conditions related to a given case. Some drugs might be riskier in women compared to men, for example.
How are rheumatic skin conditions treated?
The answer to this question is complex. The skin lesions in a large number of the 100 or so diseases that cause arthritis are treated differently. For example, in a disease like lupus, the skin lesions can be treated quite nicely with cortisone-containing creams and oral medications such as the antimalarials. However, these same forms of treatment usually do not help the skin changes that we see in scleroderma.
The treatment really has to be individualized to the specific disease and to the specific conditions related to a given case. Some drugs might be riskier in women compared to men, for example.
Some drugs like the corticosteroids ("steroids") suppress the immune response in a broad fashion and can be very useful in a number of autoimmune diseases, including the rheumatic diseases (corticosteroids are commonly referred to as "cortisone" type drugs). Corticosteroids like prednisone taken by mouth can certainly suppress various manifestations of rheumatoid arthritis, including the skin changes like vasculitis.
However, long-term use of corticosteroids by mouth can produce a lot of troublesome and serious side effects. Therefore, physicians are constantly trying to find other drugs that will prevent having to rely on corticosteroids for long periods of time.
Methotrexate instead of corticosteroid
In the case of rheumatoid arthritis, methotrexate is a drug that has been found to be able to prevent patients from having to take so much corticosteroid. Generally, the things a dermatologist does to treat the surface of the skin, such as applying sunscreens and corticosteroid-containing creams or ointments, does not help the more severe skin problems such as vasculitis that are seen in rheumatoid arthritis.
What are treatment options for lupus skin disease?
Regarding treatment of lupus skin disease, the topical measures that were discussed above, such as the application of sunscreens and corticosteroid-containing creams and ointments directly to the skin, can be helpful in suppressing the skin inflammation caused by lupus.
Medications for lupus skin diseases
However, most skin lupus patients do require some type of oral therapy in addition to the topical therapy. The safest form of oral therapy to treat lupus skin disease would be one, or a combination, of the anti-malarial drugs, such as hydroxychloroquine, which is commonly referred to by its trade name: Plaquenil. This drug can be used very safely if the common recommended guidelines concerning total daily dosage are followed. However, patients need to have their eyes monitored while on this drug since on rare occasion problems can develop in the retina of the eye while on this form of treatment.
How are skin problems from dermatomyositis treated?
Similar forms of treatment are used for the skin problems seen in patients with dermatomyositis and lupus. Dermatomyositis causes autoimmune inflammation and damage in the muscles, skin, and occasionally other vital organs, such as the lungs.
However, dermatomyositis skin disease generally is harder to treat than is lupus skin disease. In addition, dermatomyositis skin disease is often more troublesome for the patient by producing symptoms such as itching (lupus skin disease usually does not itch).
How does scleroderma affect the skin?
Scleroderma is a term that just means 'hard skin.' Like lupus, patients having scleroderma skin changes have a variable risk for having associated damage to internal organs, especially the kidneys and lungs.
Some patients develop a form of scleroderma that never goes on to cause damage to internal organs. This form of the disease is called localized scleroderma or morphea. However, other patients with scleroderma do develop internal complications relatively soon after the onset of skin problems.