Porth's Essentials of Pathophysiology, 4e

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Musculoskeletal Function

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(i.e., reticular cyanotic discoloration of the skin, often precipitated by cold), and fingertip lesions. Hair loss is common. Mucous membrane lesions tend to occur dur- ing periods of exacerbation. Sun sensitivity may occur in SLE even after mild exposure. Renal involvement is common in SLE and a signifi- cant cause of morbidity and mortality. 45 Several forms of renal involvement may occur, including glomerulone- phritis, tubulointerstitial nephritis, and vascular disease (see Chapter 25). The clinical manifestations of renal involvement range from asymptomatic hematuria and/or protinuria to frank nephrotic syndrome with progressive loss of renal function. Nephrotic syndrome causes pro- teinuria with resultant edema in the legs and abdomen, and around the eyes. Kidney biopsy is the best determi- nant of renal damage and the type of treatment needed. Pulmonary involvement is manifested primarily by pleural effusions and/or pleuritis. 45 Pleural effusions are typically small, bilateral, and exudative. Up to 50% of persons with SLE develop pleuritis, which is manifested by pleuritic chest pain. The presence of pleuritis usually corresponds to active SLE in other organ systems. Cardiovascular disease is a frequent complication of SLE. It can involve the pericardium, myocardium, or coronary arteries. Pericarditis, with or without effu- sion, is the most common cardiac manifestation in SLE, occurring in 50% of persons with SLE at some point during the course of their disease. 45 Coronary heart dis- ease is also increased in persons with SLE. Hypertension may be associated with lupus nephritis and long-term corticosteroid use. Hematologic disorders may mani- fest as hemolytic anemia, leukopenia, lymphopenia, or thrombocytopenia. The nervous system is involved in persons with SLE. 45 Involvement of both the central (CNS) and peripheral (PNS) nervous systems occurs. Central nervous system disorders range from diffuse processes such as headache, psychosis, and mood disorders to more focal processes such as seizures. Headaches are reported in more than 50% of persons with SLE, with both migrainous and tension-type headaches being described. 45 Psychotic man- ifestations include depression and unnatural euphoria, as well as decreased cognitive functioning, and confusion. Chronic discoid cutaneous lupus is a disease char- acterized by plaquelike lesions on the head, scalp, and neck. These lesions first appear as red, swollen patches of skin, and later there can be scarring, depigmentation, and plugging of hair follicles. The disease is usually confined to the skin, but after many years 5% to 10% of persons with the disorder may develop multisystem manifestations. Subacute cutaneous lupus erythematosus is a less- severe form of lupus that presents with skin lesions resembling psoriasis on sun-exposed areas such as the face, chest, upper back, and arms. Most persons have mild systemic manifestations of SLE, which usually are limited to joint and muscle pains. There is also a low incidence of lupus nephritis. Diagnosis and Treatment. The diagnosis of SLE is based on a complete history, physical examination, and

CNS symptoms Baldness

Butterfly rash

Oral ulcers

Anemia Neutropenia Thrombocytopenia

Pleuritis Pneumonitis

Pericarditis Myocarditis

Splenomegaly

Lupus glomerulonephritis

Osteoporosis

Fingertip lesions

Lymphadenopathy

Myositis

Polyarthritis

FIGURE 44-7. Clinical manifestations of systemic lupus erythematosus. CNS, central nervous system.

blood cells and platelets 43,45 (Fig. 44-7). The onset may be acute or insidious, and the course of the disease is characterized by exacerbations and remissions. Arthralgias and arthritis, the most common manifes- tations of SLE, are present in up to 90% of persons at some point during the course of their disease. 46 Although the arthritis can affect any joint, it is most often sym- metric with involvement of the small joints of the hands, wrists, and knees. Ligaments, tendons, and the joint cap- sule may be involved, causing varied deformities. Other musculoskeletal manifestations of SLE include tenosyno- vitis, rupture of the intrapatellar and Achilles tendons, and avascular necrosis, frequently of the femoral head. Skin manifestations can vary greatly and may be classified as acute, subacute, or chronic. The acute skin lesions include the classic malar or “butterfly” rash on the nose and cheeks 43,45 (see Fig. 44-7). Other skin lesions that may occur include hives or livedo reticularis