Systemic lupus erythematosus (SLE) is a multisystem disorder of unknown etiology characterized by a production of large amounts of circulating autoantibodies. This antibody production may be due to loss of T-lymphocyte control on B-lymphocyte activity, leading to hyperactivity of B lymphocytes, which leads to nonspecific and specific antibody and autoantibody production. These antibodies form immune complexes that become trapped in the microvasculature, leading to inflammation and ischemia.
Although SLE affects primarily women of childbearing age, approximately 5% of cases present in childhood, mainly around puberty. SLE is rare in children younger than 9 years of age. Although there is a female predominance of this disease in adolescence and adulthood, there is an equal gender distribution in children. The overall prevalence of SLE in the pediatric population is 10 to 25 cases per 100,000 children.
Patients with SLE can present either in an abrupt fashion with fulminant disease or in an indolent manner (Tables 90-1 and 90-2). Nonspecific symptoms are common but can be quite profound and may include significant fatigue and malaise, low-grade fever, and weight loss.
Skin disease can be a prominent finding, occurring in up to 95% of patients. A raised, erythematous rash on the cheeks, called a malar butterfly rash, is common (Fig. 90-1). This rash also can occur across the bridge of the nose, on the forehead, and on the chin. Photosensitivity can be problematic, particularly during the summer months. Both of these rashes improve with appropriate therapy. The rash of discoid lupus, by contrast, is an inflammatory process that leads to disruption of the dermal-epidermal junction, resulting in permanent scarring and loss of pigmentation in the affected area. If discoid lupus occurs in the scalp, permanent alopecia ensues because of loss of hair follicles. Raynaud phenomenon, although not specific for SLE, and livedo reticularis also can occur.
Mouth and nasal sores resulting from mucosal ulceration are a common complaint in patients with SLE and can lead to ulceration and perforation of the nasal septum. Because of reticuloendothelial system stimulation, lymphadenopathy and splenomegaly are common findings in SLE. In particular, axillary lymphadenopathy can be a sensitive indicator of disease activity. Serositis can be seen, with chest pain and pleural or pericardial friction rubs or frank effusion.
Renal involvement is one of the most serious manifestations of SLE and is common in pediatric SLE, occurring in 50% to 70% of children. Renal disease may range from microscopic
Malar butterfly rash Discoid lupus Photosensitivity Oral and nasopharyngeal ulcers Nonerosive arthritis (more than two joints with effusion and tenderness) Pleuritis or pericarditis (serositis) Seizures or psychosis in absence of metabolic toxins or drugs
Cellular casts (RBC, granular, or tubular)
Hemolytic anemia with reticulocytosis or Leukopenia (<4000 on two occasions) or Lymphopenia (<1500 on two occasions) or Thrombocytopenia (<100,000/mm3)
Evidence of presence of antiphospholipid antibodies IgG or IgM anticardiolipin antibodies or Lupus anticoagulant or False-positive VDRL for >6 mo
Positive ANA in absence of drugs known to induce lupus
ANA, Antinuclear antibody; RBC, red blood cell; VDRL, Venereal Disease Research Laboratory.