Systemic Lupus Erythematosus (Lupus) is a chronic inflammatory disease that can affect numerous organ systems, including the joints, skin, kidneys, and brain. The condition presents with a wide variety of symptoms that wax and wane over time. Because symptoms like rashes and fatigue are not always visible, many people wonder if the disease can be transmitted from person to person. This explanation details the nature of Lupus and the factors that influence its development.
Lupus is Not Transmissible
Lupus is definitively not contagious, which means it cannot be “caught” from someone else like a cold or the flu. The disease does not spread through typical infectious routes, such as coughing, sneezing, or respiratory droplets. Sharing food or drinks, kissing, or casual physical contact with a person who has Lupus poses no risk of transmission.
The disease is also not passed through blood transfusions or sexual contact. While a pregnant person with Lupus can pass certain autoantibodies to a fetus, this results in a temporary condition called neonatal Lupus. The child does not acquire the chronic, systemic disease itself. Neonatal Lupus symptoms, such as rashes, typically disappear completely within a few months after birth as the mother’s antibodies leave the baby’s system.
The Autoimmune Mechanism of Lupus
Lupus is classified as an autoimmune disease, meaning its origins are internal and not due to an external pathogen like a virus or bacteria. In a healthy person, the immune system produces antibodies to destroy foreign invaders. In Lupus, the immune system loses its ability to distinguish between foreign substances and the body’s own healthy cells and tissues.
This failure results in the production of autoantibodies, which are directed against the body’s own components, such as DNA and proteins within the cell nucleus. These autoantibodies attack various tissues throughout the body, causing widespread inflammation. This internal attack damages organs like the kidneys, heart, lungs, and joints.
The disease arises from a dysregulation within the body’s own defense mechanisms. This chronic, self-directed immune response involves the inefficient clearance of dead cells and the subsequent exposure of nuclear material that triggers the immune response.
Primary Risk Factors and Triggers
Lupus development is linked to a combination of genetic predisposition and external influences. Over 50 genes are associated with an increased likelihood of developing the condition. While having a close relative with Lupus elevates an individual’s risk to between 5% and 13%, genetics alone are rarely sufficient for the disease to manifest.
Demographic factors, particularly sex and ethnicity, are significant risk areas. Lupus affects women far more often than men, with approximately nine out of ten cases occurring in females diagnosed between the ages of 15 and 45. This strong disparity suggests a role for female hormones, such as estrogen, in the disease’s development.
The condition is also disproportionately prevalent in certain ethnic groups, including African Americans, Hispanic/Latino, Asian Americans, and Native Americans. Lupus is three times more common in Black women than in white women, and these groups often experience more severe symptoms.
Environmental triggers can initiate the disease in genetically susceptible individuals. Exposure to ultraviolet (UV) light, particularly from the sun, is a well-documented trigger that can cause skin lesions or start an internal disease flare. Certain infections, such as the Epstein-Barr virus, have also been linked to the onset of Lupus.
Furthermore, some medications can induce a temporary, Lupus-like syndrome that resolves once the medication is stopped. These include certain antibiotics, blood pressure drugs like hydralazine, and heart rhythm medications like procainamide.