Tick bites - straightforward advice for humans

Tick bites – straightforward advice for humans 

The village pharmacy where work is not far from the New Forest, an area considered a hot-spot for ticks carrying Borrelia bacteria, the cause of Lyme disease. People commonly come in to the pharmacy saying “I’ve been bitten by a tick, what do I need to do?” The public’s knowledge about ticks and Lyme disease is generally poor. So when giving advice it helps enormously that there is clear guidance from the National Institute for Health and Care Excellence (NICE) in their guideline on Lyme disease. Pet owners might be worried about the risk to humans from ticks found on their pets and so veterinary professionals are well-placed to help educate people and direct them to reliable sources of information. Some people worry that a tick can move from a cat or dog and infect a human. While this is theoretically possible it is highly unlikely. However, if a dog is picking up ticks, then the person who walks with the dog is also at risk and should check themselves regularly. 

The key NHS advice for people who have been bitten by a tick is:

  • To remove the tick as soon as possible (there is evidence that a tick has to be attached for at least 16 hours in order to be able to transmit infection)

  • Most tick bites do not transmit Lyme disease and prompt, correct removal of the tick reduces the risk of transmission. 

  • There is no need for treatment if there are no symptoms.

  • If there are symptoms, the person should be advised to consult their GP. A rash (erythema migrans) is a common symptom of early Lyme disease in humans but is not always present. Other symptoms include a mild flu-like illness including fever, headache and fatigue. 

  • If left untreated, infection can develop to late manifestations, affecting the joints, nervous system, or the heart. However, most people will never know if they’ve had Lyme disease. If treated, the long-term outcome for proven Lyme disease is very good.

More about the rash

Erythema migrans is a red rash that:

  • is not usually itchy, hot or painful

  • usually becomes visible from 1 to 4 weeks (but can appear from 3 days to 3 months) after a tick bite and lasts for several weeks

  • is usually at the site of a tick bite

  • increases in size and may sometimes have a central clearing (the characteristic bulls-eye rash). However, the rash can have a very variable appearance in humans. NICE has produced a resource with images showing the various presentations of erythema migrans. 

Diagnosis and treatment

The NICE guideline states that a diagnosis of Lyme disease can be made in people with erythema migrans without laboratory testing because the rash is specific to Lyme disease and prompt treatment will prevent further symptoms developing. If there are other symptoms but no rash laboratory testing is indicated to ensure accurate diagnosis and appropriate treatment, because most other symptoms associated with Lyme disease have other, more common, causes. 

Following a diagnosis, the standard treatment for Lyme disease is a 3-week course of doxycycline. 

If there are no symptoms, a diagnosis of Lyme disease is not made, even if the person has had a tick bite. Prophylactic antibiotics are not recommended. 

Helpful information 

Information on human tick bites (including how to remove ticks) and on Lyme disease is available on the NHS Website – Lyme disease https://www.nhs.uk/conditions/lyme-disease/

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