Leech bites: Removal and treatment

While leeches instill fear in many Australians, their bites are generally painless and harmless. Knowing how to correctly detach a leech and treat a leech bite can help you avoid unnecessary infections.

At nib, we consider ourselves your health partner, working with the experts to give you the tips and tricks to live your healthiest life yet. So, we spoke with nib Medical Advisor Dr Hamish Black to find out everything you need to know about leech bites and how to treat them.  

Leeches are segmented worms that latch onto the skin and introduce an anticoagulant that allows them to feed on the host’s blood. Leeches generally live in freshwater, but some species can be found in the ocean or on the ground or in low foliage in wet rainforests. 

While some bleeding can be expected once the leech is removed, adverse reactions to leech bites are rare. Some people may be allergic to leech bites and should seek medical attention. 

Detaching the leech 

If left untreated, the leech will usually fall off after about 20 minutes when it becomes swollen with blood. But most people aren’t comfortable with allowing a leech to feed on them for 20 minutes and prefer to get rid of it as soon as possible.

“Applying saltwater, salt or vinegar to a feeding leech will cause it to fall off,” says Hamish. 

Things to avoid: 

• Pulling the leech off if your skin is at all fragile: Your skin may tear and ulcerate, or part of the leech’s jaw could stay in your skin, leading to infection 

• Applying heat: Using a lighter, lit cigarette or hot coal may result in burns to your skin  

Once the leech is removed, some simple aftercare measures can help treat the bite and avoid any complications. 

“Wash the bite site with soap and water and apply pressure until bleeding ceases,” advises Hamish. You can also apply a cold pack to relieve any pain or swelling. 

You should seek medical attention if: 

• The bite becomes red, hot or infected  

• A wound or ulcer develops 

• You have an allergic reaction 

Taking a few precautions can help prevent leech bites. When you’re walking through the bush or rainforest areas, wear a long-sleeved shirt, long pants, closed shoes and socks tucked into your pants. Using insect repellent containing DEET can also keep leeches at bay.

If you choose to swim or walk through freshwater or stagnant waterways, check yourself and children for leeches afterwards.  

Please note: The tips throughout this article serve as broad information and should not replace any advice you have been given by your medical practitioner.