SKIN DISEASE IN LUPUS

Thomas T. Provost, M.D.
Noxell Professor and Chairman
Department of Dermatology
The Johns Hopkins School of Medicine, Baltimore, MD

Skin disease is very common in lupus erythematosus. It ranks second only to arthritis in frequency of occurrence. Approximately 20% of people with systemic lupus erythematosus (SLE) will have ring-shaped or coin-shaped, scarring lesions as the initial symptom of their disease. In addition, it has been estimated that as many as 60-65% of people with SLE will develop skin rashes or lesions at some time during the course of their illness. However, with the use of oral steroids (Prednisone), and anti-malarial drugs (hydroxychloroquine, or Plaquenil), the occurrence of these skin lesions is now less frequent.

The skin rashes and lesions of lupus erythematosus can be divided into those that are specific to lupus and those that can occur in other diseases as well as lupus (non-specific lesions). There are two specific lesions associated with lupus erythematosus: discoid lesions (characteristic of discoid lupus erythematosus), and coin-shaped, non-scarring lesions (characteristic of subacute cutaneous lupus erythematosus).

Discoid Lesions

The term discoid is a very confusing term which, unfortunately, is inappropriately used by many people, including physicians. The term discoid simply means coin-shaped. The scarring coin-shaped lupus lesion commonly seen on areas of the skin that are exposed to light has been termed discoid lupus erythematosus. This term refers only to the description of the lupus lesion on the skin and should not be employed to distinguish cutaneous lupus from systemic lupus erythematosus. A physician cannot determine whether or not a discoid lupus lesion on the skin is occurring in the presence or absence of systemic features just by examining the shape of the lesion. This can only be done by taking a complete history and physical examination and interpreting the results of appropriate blood tests.

What is the relationship between discoid and systemic lupus erythematosus? This is a common question. Lupus erythematosus should be viewed as a continuum of a spectrum of the disease. At one end of the spectrum, in its most mild form, it is characterized by coin-shaped, scarring, skin lesions which we term discoid lesions. At the other end of the spectrum are those systemic lupus erythematosus patients who have no skin lesions, but have systemic features (i.e., arthritis or renal disease). People with only discoid lesions and no systemic features commonly have no auto-antibodies in their serum (i.e., antinuclear or anti-DNA tests will be negative). On the other hand, people with systemic lupus erythematosus are characterized by the presence of one or more types of auto-antibodies in their blood. From personal experience and from reviewing the literature, it has been estimated that between 5 and 10% of patients initially presenting with only the coin-shaped lesions of discoid lupus will, with time, develop systemic features. As noted above, approximately 20% of people with systemic lupus erythematosus will at the time of the initial presentation of their disease have discoid lupus lesions. These data indicate that, at times, the lupus disease process is dynamic and, with time, a small percentage of those patients who only have discoid lupus lesions will eventually develop systemic disease. In addition to these coin-shaped, scarring lesions, there are several different types of discoid lupus lesions with which patients should be familiar. Occasionally, the discoid lupus lesions may occur in the scalp producing a scarring, localized baldness termed alopecia. At times, these discoid lesions may appear over the central portion of the face and nose producing a characteristic butterfly rash.

This type of lupus obviously has significant cosmetic implications. The discoid lupus lesions may develop thick, scaly (hyperkeratotic) formations and are termed hyperkeratotic or hypertrophic cutaneous lupus lesions. Discoid lupus lesions may also occur in the presence of thickening (deep induration) of the layers of underlying skin. This is termed lupus profundus.

At the present time, research indicates that discoid lupus lesions are the result of an inflammatory process in the skin in which the patients' lymphocytes (predominantly T-cells) play a major role. This is in contrast to systemic lupus erythematosus, where autoantibodies and immune complex formation are responsible for many of the clinical symptoms.

Subacute Cutaneous Lesions

The second type of specific lupus lesion was most recently described by Sontheimer and Gilliam during the late 1970's. This lesion is characterized as a non-scarring, erythematosus (red), coin-shaped lesion which is very photosensitive (gets worse when exposed to UV light). This type of lesion, which is characteristic of subacute cutaneous lupus, occurs in lupus patients who, approximately 50% of the time, demonstrate features of systemic lupus erythematosus. Renal disease, however, is unusual in these patients. These skin lesions also occur in people who only have clinical evidence of skin disease, and do not show any symptoms of systemic lupus. Approximately 70% of people with these lesions have anti-Ro (SSA) antibodies.

The subacute cutaneous lupus lesion can sometimes mimic the lesions of psoriasis or they can appear as non-scarring, coin-shaped lesions. These lesions can occur on the face in a butterfly distribution, or can cover large areas of the body. Unlike the discoid lupus lesions, these lesions do not produce permanent scarring, but can be of major cosmetic significance.

Lesions of subacute cutaneous lupus may also be seen as a feature of neonatal lupus syndrome. Infants with neonatal lupus, born of mothers with anti-Ro (SSA) antibodies, may develop a transient lupus rash that disappears by the time they reach 6 months of age. At the present time, the best evidence suggests that the anti-Ro (SSA) antibody is passed via the placenta to the fetus and plays a major role in causing the characteristic lupus skin disease.

Non-Specific Lupus Lesions: Hair Loss

The non-specific lupus lesions include several forms of hair loss (alopecia) which are not related to the presence of discoid lupus lesions in the scalp. Systemic lupus patients who have been severely ill with their disease may (over a period of time) develop a transient hair loss in which large amounts of hair evolve into a resting phase and fall out. However, this is quickly replaced by new hair. In addition, a severe flare of systemic lupus erythematosus can result in defective hair growth which causes the hair to be fragile and to break easily. The hair is broken off above the surface of the scalp, especially at the edge of the scalp, giving the characteristic appearance termed "lupus hair".

Vasculitis

Systemic lupus erythematosus patients may develop inflammatory disease of the blood vessels (vasculitis). The cutaneous manifestations of vasculitis are varied. The lesions may appear as red welts involving large areas of the body. These lesions can also present as small red lines in the cuticle nail fold or on the tips of the fingers or as red bumps on the legs. In addition, these red bumps may ulcerate. At times, the blood vessels that are involved in this inflammatory process may be deep in the skin producing painful, red nodules. These are usually found on the legs.

Photosensitivity

Photosensitivity is a common feature of lupus erythematosus. The overwhelming majority of specific lupus lesions (i.e., discoid lesions and subacute cutaneous lupus lesions) occur on sun-exposed areas. In addition, approximately 40-70% of people with lupus will note that their disease process, including the skin disease, is aggravated by sun exposure. Furthermore, people with subacute cutaneous lupus erythematosus, especially those who have anti-Ro (SSA) antibodies demonstrate pronounced photosensitivity. It has been estimated that 90% of patients with systemic or discoid lupus who have anti-Ro (SSA) antibodies are photosensitive. Furthermore, a number of these patients are so photosensitive that they will burn through window glass. Window glass filters out sunlight in the sunburn spectrum and protects normal people from developing a sunburn. However, window glass will not filter ultraviolet light of longer wavelengths and these wavelengths are capable of exacerbating (making worse) the skin lesions in people with lupus with anti-Ro (SSA) antibodies.

One recent study has shown that ultraviolet light in both the sunburn and long wavelength light spectrum (those wavelengths that are not blocked by window glass) will cause lupus lesions to appear on the skin of patients with systemic lupus erythematosus, those with the lesions of subacute cutaneous lupus, and those who have only scarring lupus lesions (discoid lesions) with no evidence of systemic disease. These data provide excellent evidence for the role of ultraviolet light in the development of lupus skin lesions.

There is clinical and experimental evidence that shows that ultraviolet light can also induce flares in people with systemic lupus erythematosus. The way that ultraviolet light triggers these systemic flares (or leads to the development of skin lesions) is not known. However, there is evidence that suggests that ultraviolet light is capable of leading to an increase in the number of auto-antigens to which the person is reacting.

Treatment

The treatment of skin disease in lupus erythematosus involves the use of a number of drugs as well as the use of sunscreens. Individual lupus lesions can be treated with the topical application of steroid creams, the application of a steroid impregnated tape to cover the lupus lesion, or the intralesional injection of low doses of steroid. Widespread lupus lesions are frequently treated using hydroxychloroquine (Plaquenil) alone, or in combination with, a short burst of oral steroids. On very unusual occasions, unmanageable, cosmetically objectionable lupus lesions have been successfully treated with vitamin A derivatives (such as Tegison).

Sun protection can do a lot to prevent the development of lupus skin lesions. People with lupus should avoid prolonged periods of exposure to sunlight, especially between the hours of 10 am and 3 pm, when the sun is at its brightest. It is also a good idea to wear a wide-brimmed hat and avoid clothing made of thin fabric which will admit sunlight. In addition, the regular use of sunscreens with a sun protective factor rating of SPF 15 will also provide protection. In recent years, research has shown that ultraviolet light of long wavelengths, as well as ultraviolet light in the sunburn spectrum, is capable of producing lupus skin lesions. Sunscreens capable of blocking this long wave ultraviolet light are now available. In contrast to ordinary sunscreens which generally contain paraminobenzoic acid (PABA) esters and benzophones, these sunscreens are actually sunblocks and contain titanium oxide.

For specific information regarding the treatment of various skin manifestations of lupus erythematosus, as well as the employment of sunscreens, consult your dermatologist, or your local chapter of the Lupus Foundation of America.

The Lupus Foundation of America

The purpose of the Lupus Foundation of America (LFA) is to assist local chapters in their efforts to provide supportive services to individuals living with lupus, to educate the public about lupus, and to support research into the cause and cure of lupus.

Volunteers, through an extensive network of over 500 constituent chapters, branches, support groups and International Associated groups, provide the majority of services which link the Lupus Foundation to thousands of lupus patients and their families.

The LFA sets standards and provides direction and general support to its chapters, leading the efforts to operate a patient-oriented, non-profit, voluntary health agency in an ethical and professional manner. The LFA has developed specific services and programs to provide chapters with assistance in meeting patients' needs and organizational goals. These include chapter support, volunteer leadership training, research, patient education programs, public awareness activities, professional education, advocacy, and resource development.

lupus@piper.hamline.edu

Last modified: 1996-07-30