Lupus Disorders
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Posted by Elaine Moore Nov 5, 2006 |
The word lupus is derived from the French word for wolf, and it refers to the characteristic malar facial rash seen in this disorder. Although the word lupus usually suggests a condition of systemic lupus erythematosus (SLE), which is the most common form of lupus, there are four distinct types of lupus that cause disease. The four lupus disorders include:
- Systemic lupus erythematosus (SLE)
- Neonatal lupus
- Discoid lupus
- Drug-related lupus (DRL).
The most common symptom in the lupus disorders is joint pain, followed by fever and rash.
SYSTEMIC LUPUS ERYTHEMATOSUS (SLE)
Systemic lupus erythematosus (SLE) is the most serious of the lupus disorders. Symptoms vary over time, ranging from mild to severe, and periods of remission tend to alternate with disease flares. Most symptoms of can be controlled with medications, and most serious complications occur when lupus affects the lungs, kidneys or heart. With the advent of effective therapies, the 20-year survival rate for SLE is close to 70 percent, with more than 90 percent of patients surviving for more than 5 years after diagnosis. Most mortality in SLE is associated with thrombosis or clotting, carditis, pneumonitis, pulmonary hypertension, stroke, myocardial infarction, and stroke.
Symptoms in SLE include joint pain, fever, hives, weight loss, sensory neuropathies, hemolytic anemia, fatigue, malaise, loss of appetite, nausea, malar, butterfly rash over the cheeks and bridge of the nose, discoid rash, light sensitivity, painful or painless mouth and nose ulcerations, cognitive dysfunction, seizures, headaches, pulmonary complaints, chest pain, shortness of breath, cough, abdominal pain, atherosclerosis, systolic murmurs, clotting abnormalities, pericarditis, uremia, and vasculitis. SLE can also affect the orbit or eye socket, the eyelid, the optic nerve, and the blood vessels that surround the retina.
NEONATAL LUPUS SYNDROME
A small number of infants born to mothers with SLE may develop mild transient lupus symptoms caused by a passive transfer to maternal antibodies into the fetal blood circulation. Because infants do not make these antibodies, the symptoms of neonatal lupus only persist for 2-3 months at which time the antibodies break down and exit the blood circulation.
Neonatal lupus only occurs in babies whose mothers have antibodies to Ro (SS-A) or La (SS-B) antigens. The most common symptom is a self-limiting skin rash, which may be severe. Rarely, babies with neonatal lupus may have a permanent heart block secondary to a conduction defect. This condition may require treatment with a cardiac pacemaker.
DRUG-RELATED LUPUS
Drug-related lupus (DRL), which is also known as drug-induced lupus is an autoimmune disease variant related to long-term use of certain medications, notably procainamide, quinidine, minocycline, and hydralazine. A number of other drugs are also suspected of triggering DRL and of causing disease flares in patients with SLE. DRL resolves shortly after the responsible medication is withdrawn. DRL rarely causes kidney or lung problems, and is usually characterized by arthralgia and a positive test result for antinuclear antibodies (ANA).
DISCOID LUPUS ERYTHEMATOSUS (DLE)
Discoid lupus erythematosus (DLE), which is also known as cutaneous lupus, is a chronic skin condition characterized by inflammatory skin lesions that may occur on the face, ears, scalp and other parts of the body. These lesions appear as an inflamed growth with scaly and a warty-like appearance. The center areas may appear lighter in color and tend to be surrounded by a darker (hyper-pigmented) area, which is darker than the normal skin tone. Scalp lesions can cause hair loss. Approximately 20 percent of patients with discoid lupus have antinuclear antibodies, and a small number of patients may have kidney involvement, a positive rheumatoid factor test, or low levels of complement.
Discoid lupus can occur in patients with SLE and in a small number of patients (less than 5 percent) discoid lupus can progress to SLE. Some patients with discoid lupus also have the lesions characteristic of subacute cutaneous lupus erythematosus and some may develop a malar, butterfly rash. Patients with widespread involvement often have blood disorders and are more likely to develop SLE.
Discoid Lupus in Canines
In canines, discoid lupus tends to affect the nose, causing a scaling that results in a smooth appearance. In both humans and canines, the lesions may be triggered and symptoms exacerbated by exposure to sunlight.
The lesions in discoid lupus can cause permanent scarring and hair loss. Biopsies of lesions show deposits of antibodies or complement at the dermal-epidermal junction. Symptoms tend to wax and wane although patients rarely develop permanent remission.
Protective measures include the use of sunscreens and avoidance of sun exposure. Discoid lupus is usually treated with topical corticosteroids and antimalarial compounds such as Plaquenil. Topical calcineurin inhibitors and retinoids are also reported to be helpful. In severe cases, immunosuppressives such as methotrexate, mycophenolate mofetil, and azathioprine are used. Surgery, including laser therapy, is sometimes used to excise scarred lesions or to reduce lesions with prominent capillary involvement.
Lupus panniculitis
Lupus panniculitis is a form of chronic cutaneous lupus erythematosus that may be accompanied by the typical lesions of discoid lupus. In addition, lupus panniculitis may occur in patients with SLE as a cutaneous manifestation.
Resources:
Jeffrey Callen, Lupus Erythematosus, Discoid, eMedicine, Feb 8, 2006.
David Lamont, Systemic Lupus Erythematosus, eMedicine, Jan 17, 2006.
Elaine Hay and Michael Snaith, ABC of Rheumatology: Systemic Lupus Erythematosus and Lupus-Like Syndromes, British Medical Journal 1995;310: 1257-1261.
Elaine Moore, Autoimmune Diseases and Their Environmental Triggers, Jefferson, NC: McFarland and Company, 2002.