Migraine may affect as many as 9% of all schoolchildren and often presents with abdominal symptoms of
pain,
nausea, and
vomiting. Even though the pathophysiology of
migraine remains unknown, self-regulation techniques appear to be more effective in prevention of childhood
migraine than conventional
pharmacotherapy which is often associated with adverse effects. Mast cells have been implicated in the pathogenesis of
migraine in adults, but have not been previously studied in children with
migraine. Mast cells are found close to the vessels and nerves in the meninges where they can release multiple vasoactive, neurosensitizing, and pro-inflammatory mediators. Therefore, we investigated whether children with
migraine may have increased urinary levels of mast cell mediators and whether practicing relaxation imagery exercises has an effect on the frequency of
headache, as well as on mast cell activation. Urine was collected for 24 hours from children with and without
migraine after a 5-day
amine-restricted diet. Children with
migraine also collected urine during
migraine episodes. The mean levels of urinary
histamine, its main metabolite, methylhistamine, and the mast cell
enzyme,
tryptase, were higher in children than generally found in adults, but they did not differ statistically in any of the categories studied. However, in 8 of 10 children who practiced relaxation imagery techniques and successfully reduced the number of
migraines, the urine
tryptase levels were also significantly lower. There was no relationship between successful practice and sex or age of the child. These results suggest that stress may activate mast cells which could be involved in the pathophysiology of
migraine.