Some scientists believe that the immune system in lupus is more easily stimulated by external factors like viruses or ultraviolet light. Sometimes, symptoms of lupus can be precipitated or aggravated by only a brief period of sun exposure.
Mõned teadlased usuvad, et immuunsüsteemi lupus kergemini stimuleeritud välised tegurid nagu viirused või ultraviolettkiirguse.