Dr Sarah Jarvis
My Weekly’s favourite GP from TV and radio writes for you
Lyme disease has probably been around for a long time, but it was only recognised about 40 years ago. It’s due to an infection from a germ called borrelia, which lives in the guts of small ticks. These ticks are usually around the size of a pin-head, but they can swell up to almost a centimetre long when they’re full of food. That food is blood, which they suck when they lock onto the skin of their host.
So here’s how the lifecycle goes. Ticks hatch from eggs, usually in spring. These develop into larvae, which latch onto a host (like mice or birds). That’s where they can get infected with the borrelia germ. From there they develop into “nymphs” and then adult ticks. Both of these can bite humans, although they also feed on other mammals like mice, rats or deer.
While they’re waiting for a host to feed from, they climb onto grass or other vegetation until the host brushes past them – they can’t jump or fly. That means you’re most likely to be bitten in woodland and moors like Exmoor, the Lake District, the North Yorkshire Moors and Scottish Highlands.
If you do get infected, the first sign is usually a red “bulls eye” rash that spreads out in a ring from a central red spot. It can start from 3-30 days after you’re bitten, and last for several weeks. You may feel generally poorly and tired, with a fever, muscle and joint pain. Not everyone gets the rash, and it’s less common if you catch Lyme disease in the USA. This is called “stage 1 Lyme disease”.
LYME DISEASE IS RELATIVELY UNCOMMON – 750 UK CASES WERE CONFIRMED IN 2015 – BUT IT’S STILL WORTH TAKING PRECAUTIONS TO AVOID TICK BITES
If you’re bitten by a tick, you won’t routinely be treated because most ticks don’t carry Lyme disease. But if you get any of these symptoms, especially if you’ve been in a high-risk area for ticks, it’s very important to see your GP to get treatment with antibiotics. At this early stage, treatment usually clears the infection and prevents later stages of the disease.
Many people who get stage 1 disease don’t go on to get long term complications, even without treatment. But if you’re not diagnosed and treated at stage 1, you can develop more severe problems.
Stage 2 disease starts a few weeks or months after you’re bitten, with various combinations of joint pain, nerve weakness, or inflammation of the brain, brain covering (meningitis) or heart. Later still, it can cause confusion, mood changes, or memory loss and problems.
There’s controversy over treatment for later stages of Lyme disease. For instance, long term antibiotics can cause serious side effects, and the evidence they help is limited. If your GP suspects you might have stage 2 or 3 Lyme disease, they’ll refer you to a specialist team. Most ticks aren’t infected with borrelia, and the biggest risk of Lyme disease comes if a tick is attached to your skin for over 24 hours. Simple precautions can cut risks: ◆ Tick bites don’t hurt, so it’s essential to check when you come indoors ◆ Most tick bites happen from late spring to autumn ◆ Wear long sleeved shirts and socks tucked into trousers ◆ Stick to paths and stay away from long grass ◆ Use a tick repellent spray ◆ Invest in fine-toothed tweezers or a tick-removal device (from vets). If you find a tick, grip it as close to the skin as you can, and pull away gently.
THE QUICKER YOU REMOVE A TICK ONCE YOU’RE BITTEN, THE LOWER THE CHANCE OF GETTING LYME DISEASE – CARRY TWEEZERS IN GRASSY AREAS!
Next Week: Blood Cancer