Many scientists, but not all, believe that lupus is the result of a combination of factors within the body (internal triggers -meeting factors outside the body (external triggers). One of those internal factors/agents might be a hormone. An example might be an individual with elevated hormone levels (internal agent) who encounters any number of environmental triggers.
These same scientists have not identified a specific environmental trigger, but their theory seems plausible and from where I sit, possible. Assuming hormones are one of those internal agents, they can make an individual more susceptible to developing lupus, particularly the hormone, estrogen. Both men and women have hormones, but they are present with more regularity in women.
If this hormonal theory is correct, is it any wonder, then, that more women than men (90%) develop lupus? It has also been seen that before and during their menstrual cycles (when estrogen production is higher). This also occurs in pregnancy. But, this cause/effect theory is hard to prove, because there are many women with lupus who take birth control pills (heavy with estrogen), or other forms of estrogens and they don’t see an increase in their lupus symptoms-or many don’t have lupus, at all.
There is no specific gene that one can test for that is a predictor of lupus; but lupus can run in families. A genetic link with environmental factors has some thinking; when fraternal twins are raised in the same environment, only one may develop lupus. But if the twins are identical, there is a much greater chance (about 25%) of lupus developing.
So what of environmental triggers? As discussed earlier, it is hypothesized that susceptible individuals need to be confronted with environmental triggers before lupus develops. What might some of these environmental triggers be? They can be ultraviolet rays from sun and even fluorescent light bulbs. medications which cause sun sensitivity (like tetracycline), sulfa drugs (Bactrim and others), penicillin or some other penicillin-based antibiotics, stresses on the body (physical and emotional) or pregnancy.