Systemic Lupus Erythematosus (SLE), commonly known as lupus, is a chronic systemic autoimmune disease. In lupus, the body’s defense system becomes hyperactive, causing widespread inflammation that can affect many different parts of the body. Lupus is not contagious and cannot be passed from one person to another through contact. It is impossible to contract lupus through saliva, blood, or any other bodily fluid.
Lupus Is Not Transmitted by Saliva
Lupus is fundamentally different from infectious diseases, which are caused by transmissible viruses or bacteria. The condition cannot be spread through respiratory droplets released during coughing or sneezing. Activities involving saliva, such as kissing, sharing eating utensils, or drinking from the same glass, pose zero risk of transmission. Lupus does not result from an external pathogenic agent that can be passed between people, allowing those with lupus to engage in normal social interactions without concern for spreading the disease.
The Autoimmune Nature of Lupus
The reason lupus is not contagious lies in its classification as an autoimmune disorder. Normally, the immune system produces antibodies to protect the body by targeting foreign invaders. In a person with lupus, however, the defense system mistakenly identifies the body’s own healthy cells and tissues as threats. This error causes the immune system to launch an internal attack, leading to chronic inflammation and damage.
This misdirected attack can affect almost any organ system, including the joints, skin, kidneys, heart, and brain. For example, it can cause inflammation in the kidneys (lupus nephritis) or result in the characteristic butterfly-shaped rash across the cheeks and nose. Unlike an infection, which requires a pathogen to move from host to host, lupus is an internal dysfunction of the body’s self-recognition mechanisms.
How Lupus Develops
While lupus is not infectious, its development is complex and involves a combination of factors. Experts believe that lupus arises from a genetic predisposition interacting with environmental triggers. Numerous genes have been identified that may increase a person’s vulnerability to the disease, and having a close relative with lupus slightly increases this risk.
Environmental factors do not cause lupus directly but may act as triggers for immune system dysfunction in genetically susceptible individuals. These triggers can include exposure to ultraviolet (UV) light, certain infections, and specific medications. Hormonal factors also play a role, given that women are affected significantly more often than men, especially during childbearing years.