Abdominal migraine associated with ecchymosis of the legs and buttocks: does the symptom imply an unknown mechanism of migraine?

Abdominal migraine is one subcategory of migraine-related syndromes. Migraine is sometimes associated with facial ecchymosis, which may be accounted for by trigeminovascular activation. However, the precise mechanism of this concurrence remains unknown. Here, we describe a 9-year-old girl, who presented ecchymosis of the legs and buttock associated with recurrent, severe, non-localized midline abdominal pain. The patient has positive family history of migraine. Investigations during an attack revealed no obvious abnormalities. According to the International Classification of Headache Disorders (Second Edition), she was diagnosed with abdominal migraine. Her abdominal pain was relieved with sumatriptan, a migraine-specific serotonin(1B/1D) agonist. The ecchymosis always occurred in conjunction with abdominal pain and tended to regress after pain relief. In contrast to the local trigeminovascular activation theory that explains the ecchymosis in a migraine-related condition, the findings gained from the presented patient suggest a mechanism that involves the initial activation of the visceral nerves responsible for abdominal nociception under the predisposition of visceral hypersensitivity associated with abdominal migraine. Subsequently, ecchymosis developed in the skin region innerved by the activated nerves, possibly involving dichotomizing afferent fibers and afferent-afferent interactions via sacral spinal cord pathway or a sympathetic reflex. Taken together with the probable common mechanism of migraine and abdominal migraine, we suggest that the skin changes in migraine are associated with somatic referral of migraine headache via the trigeminal nerve pathway.