Last reviewed: 20 Dec 2020
Last updated: 13 Dec 2019



History and exam

Key diagnostic factors

  • malar (butterfly) rash
  • photosensitive rash
  • discoid rash

Other diagnostic factors

  • fatigue
  • weight loss
  • fever
  • oral ulcers
  • alopecia
  • arthralgia/arthritis
  • fibromyalgia
  • Raynaud phenomenon
  • chest pain and shortness of breath
  • venous or arterial thrombosis
  • hypertension
  • signs of nephrosis (e.g., edema)
  • lymphadenopathy
  • abdominal pain, vomiting, or diarrhea
  • nose ulcers
  • poorly localized proximal limb inflammatory pain with weakness
  • dysrhythmias (e.g., tachycardia), conduction defects, or unexplained cardiomegaly
  • central nervous system (CNS) signs: seizures, cranial nerve abnormalities, cognitive defects, psychosis
  • dysphagia

Risk factors

  • female sex
  • age 15 to 45 years
  • African/Asian descent in Europe and US
  • drugs
  • sun exposure
  • family history of SLE
  • tobacco smoking

Diagnostic investigations

1st investigations to order

  • CBC and differential
  • activated PTT
  • BUN and electrolytes
  • erythrocyte sedimentation rate (ESR) and CRP
  • antinuclear antibodies, double-stranded (ds) DNA, Smith antigen
  • urinalysis
  • chest x-ray
  • ECG
More 1st investigations to order

Investigations to consider

  • blood and urine cultures
  • antiphospholipid antibodies
  • Coombs test
  • 24-hour urine collection for protein or spot urine for protein/creatinine ratio
  • complement levels
  • creatine phosphokinase
  • plain x-rays of affected joint(s)
  • renal ultrasound
  • chest CT
  • pulmonary function tests
  • pleural aspiration
  • brain MRI
  • echocardiography
  • skin biopsy
  • renal biopsy
  • thyroid-stimulating hormone (TSH)
More investigations to consider

Treatment algorithm


Consultant Rheumatologist

Wishaw General Hospital




MMC declares that she has no competing interests.

Consultant Physician and Rheumatologist

Department of Rheumatology

Glasgow Royal Infirmary




RM holds shares in GSK to the value less than £12,000.

Dr Meng May Chee and Dr Rajan Madhok would like to gratefully acknowledge Dr Gayle McKellar, a previous contributor to this topic.


GM declares that she has no competing interests.

Peer reviewersVIEW ALL

Associate Director

Medical University of South Carolina




JCO declares that he has no competing interests.

Professor of Medicine

University of Texas Southwestern Medical Center




NJO declares that she has no competing interests.

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