| |
The white tailed spider (Lampona cylindrata) is commonly found in homes throughout Australia. It tends to hide in bedding, or within clothes left on the floor.
After a medical report in 1987, the bite of a white tailed spider was linked with necrotising arachnidism, a type of skin inflammation and ulceration. However more recent research suggests that the white tailed spider bite is probably not linked to necrotising arachnidism. Occasionally, weals, blistering or local ulceration have been reported - conditions known medically as necrotising arachnidism.
In most cases, the bite from a white tailed spider only causes a mild reaction, including itching and skin discolouration, which usually resolves after a few weeks. There are no specific first aid treatments for a white tailed spider bite, except the use of icepacks to help relieve the swelling. You should not use antibiotics. Always see your doctor if any spider bite does not clear up.
Seek advice from your local council or professional pest controllers on how to eliminate the white tailed spider from your home.
Physical characteristics of the white tailed spider
The characteristics of the white tailed spider include:
- Cylindrical body
- From 1cm to 2cm in length
- Dirty grey to brown colour
- Glossy legs
- Characteristic light coloured grey or white spot at the ‘tail’
- Two similar spots near the front of the body may also be present.
Common hiding spots
The white tailed spider is found in homes throughout Australia. It tends to be more active during summer. Favourite hiding spots include:
- Bedding
- Towels or clothes left on the floor
- Nooks and crannies
- Beneath mulch, leaves and rocks
- Beneath tree bark.
Symptoms of a white tailed spider bite
Bites can occur anywhere on the body, but most often on arms and legs. The symptoms of a white tailed spider bite can include:
- Localised irritation, such as a stinging or burning sensation
- A small lump
- Localised itchiness
- Swelling
- Discolouration of the skin
- Ulceration of the bite (in some cases)
- Nausea and vomiting (in some cases).
First aid for a white tailed spider bite
Always try to keep the spider for identification purposes if you have been bitten. First aid suggestions to treat a white tailed spider bite include:
- Apply an icepack to help relieve swelling
- See your doctor if the skin starts to blister or ulcerate.
Necrotising arachnidism
Necrotising arachnidism is a type of skin inflammation and ulceration that is caused by the bite of some spiders. Occasionally, the reaction is so severe that the person loses large amounts of skin and needs extensive skin grafts.
The white tailed spider and the black house spider, also found in Australia, have both been linked to necrotising arachnidism. However, a study published in the Medical Journal of Australia in 2003 examined 130 confirmed cases of white tailed spider bites and found that none had caused necrotising arachnidism.
The study found most bites happened indoors, in warmer months and at night. In two-thirds of cases, the spider was caught in bedclothes, towels or clothing. Most bites were painful, with some redness and itching. Nearly half the cases had a persistent, painful red lesion, but none of the lesions were found to be necrotic.
Conflicting theories on necrotising arachnidism
There is no confirmed cause of necrotising arachnidism. It is unclear why most people who are bitten have only mild reactions, while a very tiny minority suffers from skin ulceration. Researchers are divided, but current theories on the causes of necrotising arachnidism include:
- Mistaken identity – some researchers believe that white tailed spider bites aren't capable of causing skin ulceration and suggest that other spiders or other factors are to blame.
- Misdiagnosis – in rare cases, a diagnosis of necrotising arachnidism has later been found to be another condition.
- Pre-existing medical conditions – various immune system disorders or problems with the circulatory system may predispose a person to necrotising arachnidism.
Necrotic lesions
Localised skin breakdown, loss and death (necrotic lesions) can be caused by a range of other factors, including:
- Poor blood circulation (one of the most common causes of leg ulcers)
- Unmanaged diabetes
- Some fungal infections
- Some bacterial infections
- Burns, such as chemical burns.
Treatment for necrotising arachnidism
There is no cure for necrotising arachnidism. Treatment options include:
- Medications - including antibiotics and cortisone medication (corticosteroids).
- Hyperbaric oxygen therapy - oxygen delivered at higher than usual intensity and pressure.
- Surgery - the dead skin is removed and a skin graft applied.
Professional pest control treatment
Most white tailed spider bites occur inside the home where the spiders are found in bedding, towels or clothing. White tailed spiders prey on other spiders, and may help to control the population of other venomous spiders. You can control white tailed spiders in the house by clearing rooms of the webs of other spiders that attract the white tailed spider.
If you are concerned about spiders in the home, contact a qualified pest controller.
Where to get help
- Your doctor
- Australian Venom Research Unit Tel. (03) 8344 7753
- The Australian Environmental Pest Managers Association Tel. (02) 9232 8929 or 1800 25 27 72 www.aepma.com.au
Things to remember
- The white tailed spider is commonly found in homes throughout Australia.
- Most bites occur indoors, at night and in warmer months.
- The bite of a white tailed spider can be painful but is unlikely to cause necrotising arachnidism, a rare condition characterised by ulceration and skin loss.
You might also be interested in:
Bites and stings - first aid.
European wasp.
Spiders.
Want to know more?
Go to More information for support groups, related links and references.
|  |
|
