Collagen vascular diseases

Jul 01, 2007, 4:00am

Collagen vascular diseases have a wide spectrum of presentation and dermatologists are on the front line in diagnosing and treating these disorders. Traditional therapies are effective to varying degrees, but much hope for the future may rest in the hands of the emerging experimental therapies directed to control selected steps in the recently known underlying physiopathogenic pathways.

Key Points

Buenos Aires, Argentina - The cutaneous manifestations seen in the broad group of collagen vascular diseases are well-known to the experienced dermatologist.

Often, these disorders overlap clinically, serologically and histopathologically. While traditional therapies have been proven to manage these diseases, new therapies are also showing promise.

"Collagen vascular diseases have an approximate 3 percent prevalence worldwide, and mainly include scleroderma, morpheas, lupus erythematosus, dermatomyositis, rheumatoid arthritis and polyarteritis nodosa. This group of genetically determined diseases is modulated by several factors, such as environmental, infectious and therapeutic, as well as emotions or stress," says Mercedes L. Hassan, M.D., Ph.D., professor and head, department of dermatology, Ramos Mejia Hospital, University of Buenos Aires.

Lupus erythematosus (LE)

This disease is divided into chronic cutaneous LE, sub-acute cutaneous LE and systemic LE, with a variable amount of systemic involvement beyond the skin.

Photosensitivity is a disease marker.

"In general, patients should avoid sun exposure and UV sources. Using sunscreens to shield out UVB and UVA is required, and (sunscreens) should have an SPF of 30 or higher. Also, phototherapy, stress and hormonal treatments, as well as drugs that potentially aggravate LE, should be avoided," Dr. Hassan says.

Local therapy consists of topical or intralesional corticosteroids for cutaneous or mild systemic disease. As the face is most commonly involved, she says that care must be given to avoid the side effects of prolonged application. Retinoids (tretinoin 0.05 percent to 0.1 percent gel) or calcineurin inhibitors (tacrolimus 0.03 percent to 0.1 percent ointment) have also been effective for improving cutaneous lesions as long as they are applied.

Systemic therapy (hydroxychloroquine, chloroquine, thalidomide) may be necessary to treat patients under ophthalmologic, laboratory and EMG control, as well as contraceptive measures, because of its teratogenicity.

Dr. Hassan says that active systemic LE requires systemic therapy. It may exhibit nonspecific cutaneous lesions mainly due to vasculitis and organ damage (lupus nephritis) that requires pulsed methylprednisolone and cyclophosphamide. Prednisolone is useful for cutaneous as well as systemic lesions, but, again, the side effects limit its prolonged use. Azathioprine, cyclophosphamide and mycophenolate mofetil are usually given with prednisolone and are, therefore, steroid sparing.

Hydroxychloroquine is effective for widespread cutaneous diseases and may be useful in preventing new eruptions. Thalidomide can be used when antimalarials fail, and dapsone is especially effective in the bullous lesions of systemic lupus, as a single agent or associated with corticosteroids.

Secondary antiphospholipid syndrome may be associated with LE and other collagen vascular diseases. The syndrome explains the tendency of arterial and venous thrombosis, as well as obstetric and neurological manifestations that may be prominent as clinical criteria to meet this syndrome. The cutaneous lesions include livedo reticularis, chronic ulcers, livedoid vasculitis, areas of gangrene, kaposiform lesions and splinter hemorrhages.

"The 2005 Sydney Congress established two positive determinations of anticardiolipin antibodies as laboratory criteria - beta2GP1 or lupus anticoagulant, separated by a period of at least 12 weeks. Only moderate or high levels of these antibodies are significant. Prolonged antithrombotic therapy or anticoagulation may be necessary in these cases," Dr. Hassan says.

Dermatomyositis (DM)

This disease affects females two to four times more than males and is characterized by pathognomonic cutaneous lesions, photosensitivity, proximal muscle weakness and tenderness.

In addition to the cutaneous and skeletal muscle involvement, there may be an involvement of the pharyngoesophageal musculature (upper dysphagia leading to aspiration pneumonia) and heart (cardiomyopathy, arrhythmias), as well as the lung (interstitial lung disease).