The links between autoimmune diseases, infections and the environment are complex and mysterious.
But "Spondylo-arthropathies," a group of common inflammatory rheumatic disorders, appear to be triggered by environmental factors.
Rheumatoid arthritis is a chronic inflammatory autoimmune disease afflicting more than 2 million Americans.
The disorder causes your body's own immune system to attack your joints, leading to pain, deformities and a substantial loss of mobility.
One root cause of arthritis is extreme stress, and some medications, such as the birth control pills, might be linked in some cases to the onset of lupus.
Environmental pollution is also a concern for those predisposed to an autoimmune disease. Second-hand smoke, food chemicals or chemicals in the air, jet fuel fumes, UV exposure and other forms of environmental pollution are amongst the triggers considered to provoke the onset of autoimmune diseases. Hairspray and lipstick are also known to be occasional triggers.