Who should decide whether children are 'playing up' their symptoms to get a day off school? The conundrum of unilateral sweating has elicited several further accounts, with one reader, now aged 67, reporting that all his life humid weather has caused him to sweat heavily only on one side of the body. "Drawing a line bisecting my face from hairline to chin, and to a lesser degree on the rest of my body, the right side would drip with sweat while the left would remain cool and dry," he writes. This, for obvious reasons, is known as the harlequin syndrome and attributed to some disturbance of the autonomic nervous system that may be brought on by a small stroke, or be associated with some hidden cancer. In most, however, it is not possible to identify an underlying cause. Perhaps surprisingly, the defect is on the non-sweating side, where the failure of the sweating response to heat and exertion induces a compensatory excess on the contralateral side. The therapeutic options are limited, though Professor Jim Lance from Sydney, Australia - who first described the phenomenon in 1988 - reported considerable improvement following an operation known as an ipsilateral stellate ganglionectomy. This week's medical curiosity comes courtesy of Mr R B from Preston, now in his mid-fifties and plagued by a generalised soreness of the skin, "as if sunburnt." This is triggered by wearing heavy clothing and exacerbated by eating. It is usually relieved by exercise, though sometimes, paradoxically, this makes it worse. The usual blood tests are all normal, and neither a course of antihistamines nor steroids have improved matters. His family doctor is at a loss to explain what is going on. All, or any, suggestions would be gratefully received. Finally, several sharp-eyed readers noted that my recent comments on the memory-boosting effects of taking a statin holiday were at odds with the news item elsewhere in The Daily Telegraph, headlined "Statins could stave off symptoms of Alzheimer's." This referred to the findings of a research group from McGill University in Canada that giving statins to six-month-old mice improved their aptitude for learning and memory-related tasks. This is all very encouraging, not least for the drug company Pfizer, which funded the experiment. Some readers might think evidence to the contrary more compelling - such as the study a couple of years ago, by the University of California, of patients with presumed statin-induced cognitive impairment. An astonishing 90 per cent reported a marked improvement on discontinuing the drugs, leading in several cases to the reversal of a presumed diagnosis of a dementing illness. Those who reverted back to taking their statins experienced a further relapse of their mental impairment. For anyone who might wish to know more, the relevant reference is Evans and Golomb in the journal Pharmacotherapy (2009, vol 29, pp800-811). Email Dr LeFanu with your health queries (james.lefanu@telegraph.co.uk), then read his answers at telegraph.co.uk/health