but when seen are characteristic ( Fig 101.1 ) Evidence of renal disease is present in approximately 50% of children with SLE at the time of presentation, with nearly 90% developing some degree of renal involvement during the course of their disease This is significantly higher than in adult patients, in whom renal disease develops in about half Lupus nephritis is usually asymptomatic, although close questioning often reveals nocturia due to impaired renal concentrating mechanisms Edema or hypertension may be clues to involvement of the kidney Despite significant improvements in treatment, the extent of renal involvement remains the single most important determinant of prognosis in SLE, and therefore will highly influence choice of immunosuppressive therapy Thus, most children with evidence of kidney disease undergo renal biopsy to more precisely characterize the pathology and help optimize the therapeutic regimen Clinical evidence of CNS involvement may occur at disease onset or later in the course Symptoms and signs referable to the CNS include headache, seizures, polyneuropathy, hemiparesis/hemiplegia, and ophthalmoplegia Particularly in the ED setting, the clinician should be aware of the risk of stroke (both thrombotic and hemorrhagic) and of sinus vein thrombosis Chorea is the most common movement disorder and may be a presenting sign; Lyme disease (LD) and rheumatic fever must also be considered in such cases Cranial nerve palsies most commonly involve the optic nerve, trigeminal nerve, and nerves controlling the extraocular muscles Myasthenia gravis should be excluded if any extraocular muscles are involved Neuropsychiatric manifestations include mood disorders, hallucinations, memory alterations, and psychosis; rarely, psychiatric symptoms may be the first clinical manifestation of childhood lupus Pericarditis is the most prevalent form of cardiopulmonary involvement in SLE Myocarditis occurs less frequently Heart murmurs caused by valvular lesions are not common, but asymptomatic vegetations on valve leaflets are seen at autopsy in most patients (Libman–Sacks endocarditis), which is why patients with SLE are at increased risk for subacute bacterial endocarditis Myocardial infarctions have been reported in children with lupus, and the possibility of myocardial ischemia should be kept in mind if a child with lupus develops acute chest pain Pleuropulmonary involvement occurs in more than 50% of cases of SLE Unilateral or bilateral pleural effusions may occur, and pulmonary hemorrhage, although uncommon, also occurs in children with SLE Pulmonary function testing (PFT) demonstrating an elevated DLCO offers a readily available, noninvasive technique for identifying blood in the lungs Pulmonary embolus, particularly in children with antiphospholipid antibodies, also must be considered in children with the acute onset of chest pain For any SLE patient with pleuropulmonary manifestations, disease-related involvement must be distinguished from intercurrent infection, CHF, aspiration pneumonia, and renal failure Common GI manifestations include nausea, vomiting, and anorexia Persistent localized abdominal pain should suggest specific organ involvement, such as