Bites, sneezes and awful diseases

Doctors see a seasonal rise in insect bites at this time of the year, writes Maurice Gueret, as he discovers human frailty when diagnosing coughs

Ladybird bites

A rare pleasure for doctors during the pandemic has been to read about conditions other than coronavirus. Medical journals, like your newspapers, have been wall-to-wall Covid-19, with research and discussion of other matters put on hold. The British Medical Journal broke ranks of late with a wonderful educational piece on insect bites. It covered everything from the bedbug, to the Harlequin ladybird, to the tick that can cause

Lyme disease. Patients in these islands are regularly bitten but often only present to surgery when they are worried that secondary infection has set in. GPs see twice as many cases in the months of August and September. Prescriptions for flucloxacillin, a narrow-spectrum penicillin that works well against skin infection, rise by a third at this time of year. Most uncomplicated bites can be managed at home with help from your chemist. I used to mark the borders of uninfected bites at an early stage with a pen so that I could later judge whether inflammation had spread. A cool compress, antihistamine or a mild cortisone cream may help.

Medical Poirots

When a nastier insect bite presents to surgery, doctors should take a detailed history of recent patient activity, and be on the lookout for signs of shock, fever, a visible tick, pus formation, unusual rashes or spread to local lymph glands. Perhaps the most difficult job the doctor has is to tell from inspection alone whether the insect bite the patient presents with is actually a bite at all. There are clues for Poirots of the medical world.

Flea bites from pets tend to be below the knees. Spiders may leave two small puncture marks from their fangs. Bedbug bites are often multiple, happen overnight and are more likely in exposed areas free of nightclothes. Preventative measures against contracting insect bites outdoors include plenty of skin cover, especially in the early evening, tucking trousers into socks, and the use of insect repellents (picaridin is a good one) according to instructions on the label.

Disgusting coughs

‘Coughs and sneezes spread diseases’ was a slogan first used in the USA during the great influenza oubreak of 1918. I was in a queue outside Lidl during lockdown when something went down the wrong way. Embarrassed, I abandoned my spot, retreated to the car for water, and joined the queue elsewhere. A recent ‘cough and sneeze’ study in the University of Michigan asked 200 volunteers to listen to sound clips of nasty respiratory symptoms. They were asked to judge whether the hacks and snorts were produced by someone with a communicable disease or something else, such as a throat tickle. Behavioural scientists found that the more disgusting the sound was perceived to be by the listener, the more likely they were to say it was from an infected person. The listeners were often certain they were correct, but in fact they were wrong in most cases. The scientists concluded that the next time you hear someone cough or sneeze, leave the diagnosis to the doctors!