'What made you suspicious, Farrell?'
Holmes was a trifle unimaginative, but he was a stout fellow and well worth his keep, as the big problem with a meritocracy is that good servants are hard to find; when everybody's somebody then nobody's anybody.
'It was the curious incident of the cough in the night,' I said.
'But the patient did not cough in the night,' said Holmes.
'Exactly,' I said, 'and that was the curious incident.'
A symptom's absence may sometimes be as telling as its presence. Joe was an almost daily attender, could never leave without a prescription, and had as many symptoms as there are stars in the sky, so when he said he had yet another headache I was not overly concerned. Had he nausea and vomiting? Yes; was the headache worse in the morning and on leaning forward? Of course; had he double vision? No, he said, and warning bells went off and I heard the cock crow three times. For Joe to deny a symptom was as rare as an E coli UTI susceptible to trimethoprim.
There followed an urgent neurology appointment, a brain scan, a tumour, a resection, and an uncharacteristically grateful Joe.
'You're a wonderful doctor,' he said, and mindful of La Rochefoucald's maxim (to refuse praise is to wish to be praised twice), I felt that excessive modesty would have seemed churlish.
After 20 years in practice, I'm hard to shock, so I was only mildly surprised when his skin suddenly turned a bilious green, his ears grew longer and even hairier, and antennae sprouted from his head.
'I am an emissary from the planet Zarg,' he said, his voice sibilant and his breath pungent yet noxious, his forked tongue dripping acid saliva on my foot, 'our beloved Emperor Gosh has been most gravely ill for many years and I have long been seeking a physician both wise and intuitive who might provide a cure for this distressing malady. If you succeed you shall be deemed Lord of All Doctors in the Universe and our two peoples shall abide in everlasting friendship'.
'What are His Majesty's symptoms?' I asked.
'He has been bringing up green phlegm.'
'Gee whiz Joe,' I said, 'the things you'll do to get an antibiotic.'
Liam Farrell, a GP from County Armagh, Email him at GPcolumnists@haymarket.com