In response to readers' inquiries about the effects of lupus on the skin, we invited a leading local medical expert, Dr. Noursari of Johns Hopkins, to respond to your most frequently asked questions about cutaneous (also known as discoid) lupus.

What is the probability that discoid lupus will turn into systemic lupus?

Discoid lupus erythematosus (DLE) does not turn into systemic lupus erythematosus (SLE). DLE lesions can be associated with SLE. More than 20% of patients with SLE will have DLE lesions on a careful skin examination.

What signs do dermatologists look for to determine if DLE is actually turning into SLE?

Again, DLE does not turn into SLE; DLE can be associated with SLE. Only a minority of patients (less than 5%) with only DLE lesions and without any clinical signs (e.g., fever, arthritis, Raynaud phenomenon, oral ulcers, photosensitivity), serologic signs (e.g., high titers of ANA), or laboratory evidence (e.g., increased sedimentation rate, anemia, low white blood cells or low platelet, red blood cells in the urine) of systemic disease upon presentation might develop SLE in the future.

However, certain patients with DLE lesions are at higher risk for developing or having systemic disease. These are patients with:

• Generalized DLE: numerous IDLE lesions above and below the neck.
• Palmoplantar IDLE: DLE lesions on the palms and soles.
• DLE lesions associated with genetic complement deficiencies (usually there is a family history of lupus erythematosus).
• DLE lesions in a patient with very high titers of ANA (>1:640) or patients with more specific autoantibodies (anti-Ro, Sm, RNP, DsDNA). It is very pertinent to mention in this section that in my experience, although these autoantibodies are performed by several laboratories, very few of these Institutions have a standardized technique and experienced professionals.

Are there known triggers for turning DLE into SLE?

Again, DLE does not turn into SLE; DLE may be associated with SLE. The only situation in which a cutaneous disease in lupus erythematosus correlates with the systemic disease activity is in the presence of associated PHOTOSENSITIVITY (almost invariably associated with the presence of anti-Ro autoantibodies).

What is the typical amount of time that elapses between a diagnosis of DLE and a subsequent diagnosis of SLE?

For DLE patients in the high-risk category (see above), the presence of smoldering SLE features is almost the rule (e.g., arthalgias, mildly elevated sedimentation rate, low grade fever, malaise). Although, the majority of these patients do not develop overt and aggressive SLE disease, they should be followed closely by dermatologists and rheumatologists. DLE patients who are not in the high-risk category do not usually require very close follow up. Annual or biannual visits are adequate.

Which medications are effective for the treatment of cutaneous lupus?

• Topical corticosteroids: judicious use of these agents by an experienced dermatologist recommended
• Antimalarials: hydroxichloroquine is effective and safe. However, it takes more than 3 or 4 months to see any significant effect. In addition, it is very important to avoid smoking since it makes this medication less effective. Annual or biannual ophthalmologic examination is recommended. Chloroquine is not more effective than hydroxichloroquine, it is just a little quicker to start showing its effectiveness. However, it is far more toxic.

In most DLE cases, the combination of topical corticosteroids and antimalarials with sunscreen (UVB and UVA) is enough to control the disease. However, patients with more aggressive or extensive disease require:

• Systemic corticosteroid tapers, alone or in combination with adjuvants like azathioprine, mycophenolate mofetil and leflunomide.
• Cyclophosphamide, rarely required to control DLE lesions.
• Methotrexate, cyclosporine, dapsone, colchicine, gold and penicillamine, which in my experience are not effective drugs for DLE.
• Thalidomide remains an alternative drug for patients with extensive disease. Although this drug is effective and safe in the short term, prolonged use of thalidomide can be associated with peripheral neuropathy. In addition to this side effect, the hassles involved in prescribing or refilling this drug may discourage many physicians from using this effective agent.

How does hair loss (alopecia) occur in lupus patients?

• Scarring alopecia is caused by DLE on the scalp. Although significant improvement with aggressive treatment for DLE may be achieved, it usually heals with scars.
• Nonscarring alopecia is reversible and does not usually require treatment. There are two subtypes of nonscarring alopecia:
  • Telogen effluvium can be caused by any febrile disease due to SLE activity, infections or pregnancy.
  • Anagen effluvium is due to drugs like azathioprine, mycophenolate or cyclophosphamide.