Not everyone with lupus has a butterfly rash (so-named because it resembles a butterfly), also called a malar rash. A malar rash affects about half of all patients with lupus.
The butterfly-shaped rash on the cheeks and nose can happen spontaneously or after sun exposure. The rash usually looks red and raised, may be scaly, and usually does not affect the nasal folds. The butterfly rash may occur on its own, but sometimes the rash indicates an oncoming flare-up.
In addition to the butterfly rash, symptoms of lupus may include:
- Extreme fatigue
- Joint pain or swelling
- Swelling in the hands, feet, or around the eyes
- Sensitivity to light
- Fever
- Headache
- Hair loss
- Chest pain when inhaling deeply
- Sores in the mouth or nose
- Fingers and toes turning white or blue and feeling numb when exposed to cold or stress (Raynaud’s disease)
- Skin lesions
- Weight loss
- Muscle pain
- Blood clots, which can lead to stroke or seizures
- Gastrointestinal problems
- Respiratory problems
- Neurologic and psychiatric problems
- Blood abnormalities
- Swollen lymph nodes
- Eye problems
What Is Lupus?
Lupus is a chronic autoimmune disease in which the body’s immune system mistakenly attacks its own organs and tissues, causing inflammation and pain, commonly in the skin, joints, and internal organs such as the heart and kidneys, though it can affect any part of the body.
The different types of lupus include:
- Systemic lupus erythematosus (SLE)
- Cutaneous lupus erythematosus
- Drug-induced lupus
- Neonatal lupus
What Causes Lupus?
The cause of lupus is unknown, but it is believed to have genetic, hormonal, immunologic, and/or environmental triggers.
How Is Lupus Diagnosed?
There is no single test to diagnose lupus. Tests used to help diagnose lupus or to rule out other conditions include:
- Blood tests
- Complete blood count (CBC)
- Antibody tests
- Blood clotting time tests
- Erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP) levels
- Complement tests
- Creatinine
- Protein electrophoresis
- ANA
- Anti-double-stranded DNA (anti-dsDNA)
- Antiphospholipid antibodies (lupus anticoagulant [LA], immunoglobulin [Ig] G and IgM anticardiolipin [aCL] antibodies, and IgG and IgM anti-beta2-glycoprotein [GP] 1)
- C3 and C4 or CH50 complement levels
- Urine protein-to-creatinine ratio
- Serologic studies for infection
- Rheumatoid factor and anti-cyclic citrullinated peptide antibodies
- Creatine kinase (CK)
- Urine tests
- Urinalysis
- 24-hour urine collection
- Tissue or organ biopsies
- Electrocardiography
- Tests to check for pulmonary embolism
- Diffusing capacity for carbon monoxide
- X-rays of swollen joints
- Chest X-rays
- Ultrasound
- Echocardiography
- Computed tomography (CT) scan
- Magnetic resonance imaging (MRI)
What Is the Treatment for Lupus?
Lupus is usually treated with medications to help manage symptoms, such as:
- Anticoagulants
- Anti-inflammatories and steroids
- Antimalarials (to help protect skin from rashes and UV light)
- Biologics
- Immunosuppressives
Other steps to help patients manage symptoms of lupus include:
- Sun protection
- Dietary modifications
- Some patients may need increased calories
- Daily multivitamin
- Vitamin D supplementation
- Salt restriction in patients with high blood pressure (hypertension) and/or kidney inflammation (nephritis)
- Regular exercise
- Don’t smoke
- Get vaccinated as recommended by your doctor
- Influenza vaccine
- Pneumococcal vaccines
- Quadrivalent human papillomavirus (HPV) vaccine
- Hepatitis B vaccine
- Manage other medical conditions such as high blood pressure or osteoporosis
From 
https://www.lupus.org/
https://www.uptodate.com/contents/epidemiology-and-pathogenesis-of-systemic-lupus-erythematosus?search=What%20Causes%20Lupus%3F&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H7
https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-systemic-lupus-erythematosus-in-adults?search=Lupus&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1#H2215760526
https://www.hopkinslupus.org/lupus-info/lupus-affects-body/skin-lupus/