Frequently Asked Questions About Lupus

1. "How Is Cutaneous Lupus Erythematosus Diagnosed?"

The specific skin forms of lupus erythematosus have a characteristic appearance. To confirm the diagnosis, your doctor may perform a skin biopsy of affected skin. Examination of a small sample of your skin under the microscope will allow a more definite diagnosis as the microscopic tissue changes are characteristic. In addition, a small sample may be obtained for an immunofluorescence test. Lupus erythematosus is a condition in which there is antibody production to self-tissues, and these may be detected in the skin with this test.

2. "What Else Looks Like Lupus Erythematosus Of The Skin?"

Discoid lupus erythematosus can mimic many other skin diseases including psoriasis, fungal infection of the skin, and other rare inflammatory skin disorders. Subacute cutaneous lupus erythematosus can also mimic psoriasis and a common form of light sensitivity called polymorphous light eruption. In this condition, itchy bumps or welts may appear within minutes to hours after sun exposure. The malar rash of acute cutaneous lupus erythematosus can mimic rosacea, a common condition also causing redness of the cheeks. As skin lupus erythematosus can mimic many common skin conditions, a skin sample or biopsy is often required to confirm the diagnosis.

3. "Is Cutaneous Lupus Erythematosus Caused By Drugs?"

The subacute cutaneous form of lupus erythematosus can be caused by certain medications. In addition, patients with cutaneous lupus erythematosus can have their skin disease worsened by certain medications. These are rare, unpredictable side effects of these medications and in almost all such cases the association with the skin disease is only suspected and not proven. The list of suspected drugs includes certain diuretics (hydrochlorothiazide), anti-inflammatory drugs (piroxicam, naproxen, oxyprenolol), calcium antagonists used in the control of blood pressure (diltiazem), and anti-fungal agents (terbinafine). If the suspected drug is a culprit, discontinuation of the drug should result in improvement of the skin disease.

4. "What Is The Risk For Patients Presented With Cutaneous Lupus Erythematosus In Subsequently Developing Systemic Lupus Erythematosus?"

The risk of developing systemic lupus erythematosus depends of the specific form of cutaneous lupus erythematosus that is diagnosed. Only one in 10 to 20 of patients presenting with classic discoid lupus erythematosus will go on to develop systemic disease. Approximately 50% of patients presenting with subacute cutaneous lupus erythematosus or lupus profundus will develop relatively mild forms of systemic lupus erythematosus.

5. "What Causes Lupus Erythematosus?"

The skin manifestations of lupus erythematosus are the result of inflammation in the skin that is primarily mediated by inflammatory cells called T lymphocytes. How and why these T cells are activated to cause disease is still unclear. Contributing factors include a genetic predisposition and environmental factors. Genetic factors - These genes encode proteins that are important in controlling the immune system and in fighting infection. Ultraviolet light is an environmental factor that can have an adverse effect both on skin lupus and systemic lupus erythematosus. It is thought that ultraviolet light can increase cell death in the skin and thereby boost the immune response to self. Ultraviolet light can also alter the responses of the immune system itself to antigens.