Systemic lupus erythematosus
The rate of SLE varies between countries, ethnicity, and sex, and changes over time. In the United States, one estimate of the rate of SLE is 53 per 100,000; other estimates range from 322,000 to over 1 million. In Northern Europe the rate is about 40 per 100,000 people. SLE occurs more frequently and with greater severity among those of non-European descent. That rate has been found to be as high as 159 per 100,000 among those of Afro-Caribbean descent. Childhood-onset systemic lupus erythematosus generally presents between the ages of 3 and 15 and is four times more common in girls.
Lupus headache
Critics of this concept argue that there are no quality studies showing that headaches in patients with SLE differ from those in the general population. A detailed definition of the term lupus headache is lacking, since the terms "severe" and "persistent" are not quantified. Narcotic analgesics are not recommended for migraines or other common headache types. Other definitions from the IHS do not include responsiveness to treatments as a diagnostic criterion. Migraine patients are typically adult women around age 40, a demographic group in which SLE is also more common.
Some (but not all) studies have shown an association between (migraine) headaches in SLE and associated Raynaud's phenomenon and/or anti-cardiolipin antibodies.
Further studies are needed however to prove the underlying assumption that cerebral vasospasm causes migraines in lupus patients.