Abstract
Bath-related headache (BRH) is a rare primary headache syndrome consisting of recurrent attacks of headache, phenotypically resembling thunderclap headache. The syndrome is stereotypically triggered by activities that involve contact with water, such as taking a shower, soaking in a hot bath, exposure to steam, and others (1). To date all 14 reported cases of BRH were middle-aged or elderly Oriental women (1–4). We describe the first case of BHR in a middle-aged white European woman.
Case report
A 57-year-old Spanish woman, originating from Barcelona, developed an acute bitemporal headache just after diving into a warm pool and starting to swim (10 March 2004). The headache was very intense, built up rapidly to maximum intensity and was accompanied by nausea, photophobia, phonophobia and dizziness. She immediately got out of the pool and although the headache improved, it nevertheless persisted, remaining severe, together with the accompanying symptoms. She was brought to our headache clinic 3 h after the onset of the headache. On admission, physical and neurological examination revealed no abnormality apart from diffuse scalp tenderness. The patient presented neither neck stiffness nor papilloedema and she was normotensive. The following examinations were normal: routine blood tests, thyroid function, vasculitic screen, 24-h urine vanillymandelic acid, cerebrospinal fluid, magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the brain. Her clinical history was unremarkable but for a history of pure menstrual migraine, relieved by the menopause, and a recently diagnosed arterial hypertension, controlled with oral enalapril 20 mg/day. An intramuscular injection of ketorolac 30 mg relieved the headache and on day 3 the patient was discharged. The following day she woke up with a mild, bitemporal, throbbing headache that persisted for 16 days. During this period an explosive headache, having the same characteristics as the first episode, occurred each time she took a hot shower or wet her skin with hot water and, on one occasion, following vigorous coughing. Each episode lasted for up to 5 h. Oral non-steroidal anti-inflammatory drugs were ineffective, whilst ketorolac injections gave her only 4–12 h of pain relief. The patient returned to our clinic on day 17 and we prescribed propanolol 40 mg every 8 h instead of enalapril. Two days later the patient was headache free and there were no recurrences, even after repeated hot shower challenges. The results of follow-up brain MRI/MRA, performed 2 months later, were normal. At this time, because of the appearance of side-effects, propanolol was tapered off over 2 days without any recurrence of the headache and enalapril 20 mg was reintroduced as antihypertensive medication. At 18 months follow-up, the patient has not experienced any further episodes.
Discussion
This individual presents all the main clinical features of the so-called bath-related headache previously reported by Oriental authors (1–3). Indeed, as in these earlier cases, the headache (i) affected a middle-aged woman; (ii) was triggered by activites involving contact with water; and (iii) met diagnostic criteria for idiopathic thunderclap headache (5), showing a uniphasic, benign clinical course, no relapse after the initial cluster and no evidence of any structural lesion. The most remarkable aspect was that this is the first case documented in a white European woman—the white European ethnicity of the patient was traced back to her great grandparents' generation—suggesting that BRH is not exclusive to Oriental women.
The mechanism of bathing as a precipitating factor for thunderclap headache is still speculative. As suggested by Solomon and Dodick (6), idiopathic thunderclap headache may occur spontaneously or be provoked by several factors, including bathing, in predisposed individuals during periods of vulnerability. Sex, age and ethnicity seem to favour susceptibility to BRH, which is probably caused by an aberrant central sympathetic reflex triggered by skin stimulation (7) and possibly maintained by adrenoceptor-mediated sensitization of nociceptors to heat stimuli in normal skin (8). Viewed in this way, BRH appears reminiscent of a rare syndrome occurring in middle-aged women, which is referred to as ‘aquadynia’, and interpreted as an extension of the phenomenon of aquagenic pruritus. This syndrome, in which no racial preponderance has been described, consists of water-induced, short-lasting, widespread, extratrigeminal burning pain responding to sympathetic blockers (propanolol and clonidine) (9). Interestingly, in our case, propanolol administration was effective in aborting BRH, although a spontaneous remission cannot be excluded and the observation needs to be replicated before β-blockers can be considered a therapeutic option for this syndrome
In summary, this case suggests that BRH, like other phenomena thought to be mediated by aberrant autonomic neurovascular reflexes, is not exclusive to Oriental ethnic groups.