Histamine skin test in cluster headache: effects of dihydroergotamine with timed release.

The histamine skin test, as modified by Giacovazzo, was carried out on 20 patients with cluster headache and on 20 control subjects, 10 of whom suffered from migraine and 10 who were healthy volunteers not presenting any form of headache. The test was carried out before and after 30 days treatment with timed-release dihydroergotamine methanesulphonate in a dose of 10 mg/day. Data recorded on a "headache time chart" before and after treatment were evaluated by statistical analysis.