Lupus erythematosus (LE) is a collection of autoimmune diseases that is the result of immune system hyperactivity and consequent destruction of normal, healthy tissues. LE has a wide spectrum of effects on the body and targets various organs including the skin, heart, lungs, kidneys, and joints.
LE is fairly difficult to diagnose, largely owing to its mimicry of other diseases with similar symptoms. There are four main types of LE which include systemic lupus erythematosus (SLE), lupus erythematosus induced by drugs (DILE), discoid lupus erythematosus (DLE) and neonatal lupus erythematosus (NLE).
SLE
SLE is the most common and serious form of the four LE types. The etiology of SLE is not entirely understood; however, there are several predisposing factors that may contribute to the pathogenesis of this disease.
Although no exact gene has been implicated in SLE, there is believed to be a genetic predisposition to this disease, as individuals with SLE tend to have family members with other autoimmune disorders.
Moreover, there is a higher prevalence of SLE in women as compared to men. Moreover, SLE symptoms in women tend to worsen during menstruation and pregnancy. Hence, the female hormone estrogen is suspected to have some functional role in the condition.
In addition to genetics, sex, and hormones, environmental factors also play a role in the pathogenesis of SLE. Some of the different environmental triggers associated with SLE that may increase the risk of developing the disease include:
- Medications
- Infections
- Trauma
- Stress
- Ultraviolet rays
- Silica dust
- Cigarette smoking
SLE manifests at any age, with its peak incidence being between the first and fifth decades of life. Furthermore, an individual's race is another predisposing factor, with African Americans and Asians being more likely to be affected than any other group. However, this racial predisposition appears to be synergistic with environmental influences, as there is a contrast between low reported rates of SLE in black women in Africa compared to higher rates in black women in Europe.
The symptoms of SLE may vary in presentation between affected individuals and can change over time. The classic triad of symptoms associated with SLE is a characteristic butterfly rash on the cheeks and nose, as well as joint pain and fever. Additional symptoms of SLE include:
- Severe fatigue
- Swollen or painful joints
- Clotting disorders
- Anemia
- Raynaud’s phenomenon (reduced blood flow to fingers or toes in response to cold or stress causing them to turn white then blue and red).
The renal, gastrointestinal, cardiac, and pulmonary systems may also be affected in SLE. Antibody tests and urinalysis, among other diagnostic methods, are often used when SLE is suspected. Some of the different treatment regimens available for SLE include steroids, corticosteroids, and anti-inflammatory drugs.
DLE
DLE has the classical presentation of scaly plaques that range from superficial reddening of the skin to tissue around the hair roots that become blocked, have a pinkish-violet look, may occlude follicles, and even cause scarring. DLE lesions tend to favor the scalp, face, and ears. DLE may also occur in association with SLE or in the absence of systemic manifestations.
Like SLE and all other LE types, the exact etiology of DLE is poorly understood. Furthermore, the predisposing factors, incidence, and prevalence of DLE are similar to those of SLE. Exacerbation of the disease is common with exposure to the sun and the prognosis is favorable. Standard therapy for DLE includes topical corticosteroids and antimalarial drugs, which are aimed at limiting scaring and preventing the development of other lesions.
DILE
The most common culprits of DILE are hydralazine, isoniazid, and procainamide. Some of the symptoms of DILE include blurred vision, joint pain, and swelling, loss of appetite, and skin rashes that are sensitive to sunlight. Many of these symptoms will appear after using the offending drug for several months. Once DILE has been diagnosed, cessation of the causative therapy is required.
NLE
NLE presents as non-scarring lesions. Many researchers believe that NLE is caused by maternal autoantibodies, which are antibodies against one’s own tissues, that cross the placenta. NLE is commonly associated with neonatal dermatologic, cardiac, and hepatic clinical manifestations.
Most neonates with NLE tend to have spontaneous disease resolution within 6 months and therefore do not usually require intervention. In the event that the symptoms of NLE do not resolve on their own, corticosteroids and anti-malarial drugs will typically be prescribed.
References
Further Reading
Monash-led study unveils potential long-term treatment for lupus