SLE is one of several diseases known as “the great imitators” because it often mimics or is mistaken for other illnesses. SLE is a classical item in differential diagnosis, because SLE symptoms vary widely and come and go unpredictably. Diagnosis can thus be elusive, with some people suffering unexplained symptoms of untreated SLE for years.

Common initial and chronic complaints include fever, malaise, joint pains, myalgias, fatigue, and temporary loss of cognitive abilities. Because they are so often seen with other diseases, these signs and symptoms are not part of the diagnostic criteria for SLE. When occurring in conjunction with other signs and symptoms, however, they are considered suggestive.

Dermatological (Skin related) Symptoms:

30% people suffering from SLE have some dermatological symptoms and 65% suffer such symptoms at some point or the other, with 30% to 50% suffering from the classic malar rash (or butterfly rash) associated with the disease. Some may exhibit thick, red scaly patches on the skin (referred to as discoid lupus). Alopecia, mouth, nasal, and vaginal ulcers; and lesions on the skin are also possible manifestations.

Musculoskeletal (Joint & Muscle related) Symptoms:

The most commonly sought medical attention is for joint pains, with the small joints of the hand and wrist usually being affected, although all joints are at risk. The Lupus Foundation of America estimates that more than 90 percent of those affected will experience joint and/or muscle pain at some time during the course of their illness. Unlike rheumatoid arthritis, lupus arthritis is less disabling and usually does not cause severe destruction of the joints. Fewer than ten percent of people with lupus arthritis will develop deformities of the hands and feet. SLE patients are at particular risk of developing osteoarticular tuberculosis. It is suggested that there might be an association between rheumatoid arthritis and SLE and that SLE is associated with an increased risk of bone fractures in relatively young women.

Hematological (Blood related) Symptoms:

Anaemia and other iron deficiencies may develop in up to 50% of the cases. Low platelet and white blood cell counts may be due to the disease or a side-effect of pharmacological treatment. People with SLE may have an association with antiphospholipid antibody syndrome(a thrombotic disorder), wherein auto antibodies to phospholipids are present in their serum. Abnormalities associated with antiphospholipid antibody syndrome include a paradoxical prolonged PTT Partial Thromboplastin Time (which usually occurs in hemorrhagic disorders) and a positive test for antiphospholipid antibodies; the combinations of such findings are termed as lupus anticoagulant-positive. Another autoantibody finding in SLE is the anticardiolipin antibody, which can cause a false positive test for syphilis.

Cardiac (Heart related) Symptoms:

A person with SLE may have inflammation of various parts of the heart, such as pericarditis, myocarditis, and endocarditis. The endocarditis of SLE is characteristically non-infective (Libman-Sacks endocarditis) and involves either the mitral valve or the tricuspid valve. Atherosclerosis also tends to occur more often and advances more rapidly.

Pulmonary (Lung related) Symptoms:

Lung and pleura inflammation can cause pleuritis, pleural effusion, lupus pneumonitis, chronic diffuse interstitial lung disease, pulmonary hypertension, pulmonary emboli, pulmonary hemorrhage, and shrinking lung syndrome.

Renal (Kidney related) Symptoms:

Painless hematuria or proteinuria may often be the only presenting renal symptom. Acute or chronic renal impairment may develop with lupus nephritis, leading to acute or end-stage renal failure. Because of early recognition and management of SLE, end-stage renal failure occurs in less than 5% of cases.

A histological hallmark of SLE is membranous glomerulonephritis with “wire loop” abnormalities. This finding is due to immune complex deposition along the glomerular basement membrane, leading to a typical granular appearance in immunofluorescence testing.

Neuropsychiatric (Brain related) Symptoms:

Neuropsychiatric syndromes occur when SLE affects the central or peripheral nervous system. The American College of Rheumatology defines 19 neuropsychiatric syndromes in Systemic Lupus Erythematosus. The diagnosis of neuropsychiatric syndromes concurrent with SLE is one of the most difficult challenges in medicine, because it can involve so many different patterns of symptoms, some of which may be mistaken for signs of an infectious disease or stroke.

The most common neuropsychiatric disorder people with SLE have is headache,although the existence of a specific lupus headache and the optimal approach to headache in SLE cases remains controversial. Other manifestations includes cognitive dysfunction, mood disorder, cerebrovascular disease, seizures, polyneuropathy, anxiety disorder, and psychosis. It can rarely present with intracranial hypertension syndrome, characterized by an elevated intracranial pressure, papilledema, and headache with occasional abducens nerve paresis, absence of a space-occupying lesion or ventricular enlargement, and normal cerebrospinal fluid chemical and hematological constituents.

Some rare manifestations are being in an acute confusional state, Guillain-Barré syndrome, aseptic meningitis, autonomic disorder, demyelinating syndrome, mononeuropathy (which might manifest as mononeuritis multiplex), movement disorder (more specifically, chorea), myasthenia gravis, myelopathy, cranial neuropathy and plexopathy.

Other General Symptoms:

Fatigue in SLE is probably a multifactor and has been related to not only disease activity or complications such as anemia or hypothyroidism but also pain; depression; poor sleep quality; poor physical fitness and perceived lack of social support.