Lupus erythematosus is a disease that harms both physical and mental health, and it is also very likely to harm other human organ tissues such as the liver and kidneys. Therefore, everyone should have a good understanding of the relevant professional knowledge about lupus erythematosus. Generally, the diagnosis of lupus erythematosus can be made based on symptoms, medical history, laboratory tests, and other methods. It can also be diagnosed according to the American College of Rheumatology’s revised SLE diagnostic criteria, which include widespread flat cheeks, elevated, variable erythema, photosensitive diseases, and other symptoms. This method can also be used to diagnose lupus erythematosus.

4 criteria for diagnosing lupus erythematosus

Lupus erythematosus is an autoimmune disease that affects multiple systems and organs. To diagnose this disease, if it meets 4 or more of the following 11 criteria, it can be diagnosed as lupus erythematosus.

1. Cheek erythema

Diffuse flat or elevated erythema on the cheeks, usually not involving the nasolabial folds.

2. Discoid lupus

Elevated erythema covered with keratotic desquamation and hair follicle obstruction, old diseases may have skin atrophic scars.

3. Photosensitivity

Direct sunlight causes skin allergy.

4. Oral ulcers

Painless ulcers in the oral or pharyngeal cavity.

5. Arthritis

Non-adhesive arthritis, affecting two or more peripheral joints, characterized by joint swelling, pain, or effusion.

6. Pericarditis

Including pleurisy (chest pain, pleural rub, or pleural thickening effusion) and pericarditis (abnormal ECG, pericardial rub, or pericardial effusion).

7. Renal dysfunction

Proteinuria > 0.5 grams/day; the ability of cellular casts to be blood cells, hemoglobin concentration, granular casts, or mixed casts.

8. Abnormalities in the central nervous system

Blood pressure fluctuations: not pathological or metabolic disorders, such as uremia, diabetic ketoacidosis, or transient hypocalcemia. Blood neurosis: not caused by the aforementioned conditions.

9. Abnormalities in hematology

Hemolytic anemia with increased reticulocytes, low white blood cell count, reticulocytes, and platelets (excluding drug effects).

10. Abnormalities in medical immunology

Lupus cells are positive, anti-dsDNA antibodies or anti-Sm antibodies, or syphilis blood cell test positive.

11. Antinuclear antibodies

Positive immunofluorescence antinuclear antibodies (indicating pathological lupus).

Second, the causes of lupus erythematosus

1. Genetic and hereditary factors

The onset of lupus erythematosus has a familial aggregation tendency, with 0.4% to 0.5% of SLE patients’ first-degree or second-degree relatives suffering from LE or other autoimmune diseases; the incidence of SLE in monozygotic twins can reach 70% (24%～69%), while the incidence in dizygotic twins is 2%～9%; currently, more than 50 genetic gene domains related to SLE have been discovered, with common HLA II, III class genetic genes, such as DR2, DR3, DQA1, DQB1 in HLA II class D region, and C4AQ in HLA III class genetic genes.

2. Estrogen

The disease is common in women of childbearing age, and pregnancy can trigger or exacerbate SLE. However, direct evidence is still insufficient.

3. Environmental factors and others

Ultraviolet radiation can trigger or exacerbate LE, possibly both may harm the stratum corneum by producing somatic cells, causing DNA changes or the release of ‘cryptic antigens’ or new antigens, leading to the body being exposed to relative antigens, and subsequently producing immune complexes that cause damage. Medications such as hydralazine, procaine, methyldopa, isoniazid, penicillin, and others can cause pathogenic lupus erythematosus. Some infections (such as streptococcal infections, EB virus, etc.) can also trigger or exacerbate the disease.