Allodynia--perception of
pain from non-noxious stimuli--is a common clinical feature in various
pain syndromes. The significance for
migraine has increasingly been recognized and the pathophysiology has been investigated in detail.
Allodynia is a marker for sensitization of central trigeminal neurons. Intensity and persistence of allodynic symptoms are a function of duration of
migraine attacks, frequency of attacks, and
migraine history. It has been hypothesized that treatment success with
triptans may be severely impaired in the presence of
allodynia. However, randomized controlled trials did not confirm that. Treatment with
cyclooxygenase inhibitors and
dihydroergotamine does not seem to be limited by
allodynia; these medications may be able to reverse
allodynia. Data on the new class of
calcitonin-gene related-peptide antagonists are not yet available. Additional and more refined randomized controlled trials, focusing on methodological issues pertaining to the determination of
allodynia, are warranted to resolve the true relationship between
allodynia and treatment response. Regardless--based on available randomized controlled trials--the recommendation prevails to initiate abortive treatment as soon as possible after attack onset when
pain is still mild.