Button spider bites


Latrodectus indistinctus (Black button spider) is the dangerous species. [image N. Larsen ©]	Latrodectus geometricus (Brown widow, Geometric button spider) is not regarded as being dangerous. [image N. Larsen ©]

Neurotoxic envenomation results from bites by button spiders of the genus Latrodectus and is known as latrodectism. The species include the four species of black button spider: Latrodectus cinctus, Latrodectus karooensis, Latrodectus indistinctus and Latrodectus renivulvatus; and the two brown button spiders: Latrodectus geometricus (Geometric or Brown button spider) and Latrodectus rhodesiensis (Zimbabwean or Rhodesian button spider). Most of the research in South Africa was done using Latrodectus indistinctus (Western black button spider) and Latrodectus geometricus (Geometric button spider).

Bites by Black button spiders are painful and as with scorpions and snakes, the culprit is usually noticed. They are completely black, hence the name, lack the orange to red hour glass marking ventrally on the abdomen – unlike the American Black widow. Juvenile spiders have red stripes, bands or patterns. Red ventral markings may be visible in juvenile spiders. Latrodectus indistinctus has red marks dorsally which may be replaced with white speckles in the sub adult stage. These red markings reduce with each molt leaving the adult Latrodectus indistinctus totally black. Hence the species name.

The brown button spiders, Latrodectus geometricus and Latrodectus rhodesiensis are often mistaken for Black widows as they have the ventral reddish hour glass but can easily be identified as they have geometric circular patterns, often red, orange, yellow or white, which radiate down the sides of the abdomen. Although these spiders are known as “Brown” button spiders the colouring can range from a cream, dirty light green, olive green to almost black with brown being the dominant colour. The legs are noticeably darker at the joints and lighter in colour in the mid sections of the femur and tibia. All button spiders produce spherical egg cases. Those of the Black button spiders are smooth; Latrodectus geometricus egg cases are decorated with tiny spikes while Latrodectus rhodesiensis has a fluffy egg case about 2.5 times larger; otherwise the two “brown” species are difficult to separate morphologically.

Neurotoxic venom affects the neuromuscular junctions. The venom is alkaline (ph 8) and becomes acidic and less toxic at lower temperatures.

Signs and symptoms

Signs and symptoms involving latrodectism include:

sharp burning pain at the bite site, or on rare occasions trivial and not noticed;
pain spreads to lymph nodes within 5-15 minutes, which become tender and palpable;
initial hyperactivity followed by severe muscle pain and cramps, especially of large muscle groups, within an hour, resulting in tightness in the chest. Tremors are present while the weakened leg muscle make it difficult to walk;
severe pain in the chest and abdomen;
excessive salivation and watery eyes;
facial swelling (oedema), droopy eyelids (ptosis) and a painful grimace;
anxiety, slight fever, slurred speech, nausea, vomiting and headaches;
raised or reduced body temperature and a blood pressure (above 140/90mm Hg) that may rise with an increased pulse rate (tachycardia, above 100 beats per minute);
excessive sweating, resulting in clothing being soaked and a rigid board-like abdomen is present in latrodectism but absent in Parabuthus scorpion stings.
heart palpitations;
a rash might develop;
patient is extremely restless;
pins and needles (paraethesia) in hands and feet and breathing difficulties, due to tightness in chest, occasionally reported in children. It must be noticed that respiratory failure has not been recorded in South Africa; and
partial erection (priapism) reported in young males.

It is reported that globally, prior to 1965, that 1-6% of untreated cases result in death, usually as a result of respiratory failure. In fact, there have been no deaths from spider bites in South Africa in the last 60 years. Those more severely affected are children (smaller blood volume) and the elderly who suffer from respiratory or heart problems. Symptoms are less severe with L. geometricus and L. rhodesiensis, only 25-30% the toxicity of L. indistinctus. All Latrodectus bites should be and treated and monitored with equal urgency as necessary according to the signs and symptoms.

Treatment

When someone is bitten:

keep the spider, even if it is dead, if possible. An identification of the spider would be necessary to determine the appropriate treatment, if any;
keep the patient or the affected part as motionless as possible. However, this might not be practical if one is out in the wild. It is then preferable to get to help as soon as possible even if the patient has to walk;
eating, drinking and smoking should be avoided;
loosen tight clothing and remove all jewelry;
reassure patient;
call for medical assistance, a cell phone is an indispensable part of an emergency kit;
keep the patient on his/her back with feet raised above the rest of the body. Cover with a blanket and keep the head to one side in case of vomiting;
apply artificial respiration should breathing stop;
apply crushed ice to the affected area. The cold helps to retard the venom action and reduces pain. This must be done within minutes of being bitten. Do not cool for an extended period and remove periodically for the feeling to return otherwise tissue damage might result.

What you should NOT do:

do not use alcoholic drinks as this could mask certain symptoms or exacerbate them;
do not use potassium permanganate on the wound or any traditional remedies;
do not cut the wound;
do not use a tourniquet as this could aggravate local effects of the venom;
do not use snakebite or scorpion antivenom on spider bite patients;
do not waste time with pressure bandaging; and
do not give electric shocks.

It is unfortunate to see the use of pressure bandaging advocated as a first aid measure on the web and in books for treatment of snake bite as it is has shown to be ineffective when used for neurotoxic snake bites and counter productive and disastrous, restricting the blood flow, when used for cytotoxic bites (most adders and spitting cobras).

Antivenom

Latrodectus antivenom must be administered in severe proven or properly diagnosed cases of button spider envenomation. This should be done by a qualified person who should anticipate anaphylaxis, which is an allergic life-threatening reaction to antivenom. An intravenous antihistamine can be administered prior to the antivenom. Anaphylaxis is fortunately rare. Adrenaline must be administered immediately on presentation of anaphylaxis.
10 ml of antivenom must be administered intravenously diluted in 50 ml saline and administered over 15 minutes. The patient normally has a dramatic response to the antivenom showing signs of recovery within 10-30 minutes. If not, a further 5ml should be given. The patient must be monitored for 24 hours.

Differential Diagnosis

The following circumstances could be confused with getting bitten by a button spider.

Scorpion envenomation. Buthid scorpion stings result in immediate intense pain, difficulty in swallowing (dysphagia), visual disturbance and general sensitivity to touch to the skin (hyperaesthesia). Profuse sweating and abdominal rigidity is a feature of button spider envenomation but absent with scorpion envenomation.
Snake envenomation. The snake is usually seen and the painful bite is felt. Early signs and symptoms of envenomation by neurotoxic snakes result in visual disturbance, difficulty in swallowing (dysphagia) and drooping of the eyelids (ptosis).
Cytotoxic Spider Envenomation. This can be identified by the local tissue reaction and development of a necrotic skin lesion.
Acute Abdominal Pains. Pains resulting from a perforated peptic ulcer, appendicitis with peritonitis, renal colic and pancreatitis.
Myocardial Infarction. When diagnosed, cardiac problems that do not respond to treatment, one should consider Latrodectism.
Alcohol withdrawal
Organophosphate poisoning
Tetanus
Meningitis
Pneumonia
Poliomyelitis
Aneurism

Publications (by date)

Dippenaar-Schoeman AS, Newland G. 1980. The Button spiders of South Africa. Pamphlet No 146, Farming in South Africa. Printed in South Africa by the Government Printer, distributed by the Director, Division Agricultural Information, Pretoria.
Martindale CB, Newlands G. 1982. The widow spiders: a complex of species. South African Journal of Science 78: 78-79.
Newlands G, Isaacson C, Martindale C. 1982. Loxoscelism in the Transvaal, South Africa. Transactions of the Royal Society of Tropical Medicine and Hygiene 76(5): 610-615.
Maretić Z. 1986. Spider venoms and their effect. In: Nentwig, W. (ed.), Ecophysiology of spiders. Springer, New York, pp. 142-159.
Newlands G, Atkinson P. 1988. Review of southern African spiders of medical importance, with notes on signs and symptoms of envenomation. South African Medical Journal 73: 235-239.
Newlands G. 1989. Anthropods that sting and bite man – their recognition and treatment of patients. Journal of Continued Medical Education 17(7): 773-784.
Newlands G, Atkinson P. 1990. A key for the clinical diagnosis of araneism in Africa south of the equator. South African Medical Journal 77: 96-97.
Müller GJ, Koch HM, Kriegler AB, van der Walt BJ, van Jaarsveld PP. 1992. Comparison of the toxicity, neurotransmitter releasing potency and polypeptide composition of the venoms from Steotoda foravae, Latrodectus indistinctus and L. geometricus (Araneae: Theridiidae). South African Journal of Science 88:113-113.
Müller GJ. 1993. Black and brown widow spider bites in South Africa. A series of 45 cases. South African Medical Journal 83: 399-405.
Filmer MR, Newlands G. 1994. Araneism in Africa south of the equator with key to clinical diagnosis. Diseases of the Skin. 8(2): 4-10.
Lotz LN. 1994. Revision of the genus Latrodectus (Araneae: Theridiidae) in Africa. Navorsing van die Nasionale Museum, Bloemfontein 10(1): 1-60.
Schrire L, Müller, GJ, Pantanowitz L. 1996. The diagnosis and treatment of envenomation in South Africa. South African Institute for Medical Research, Johannesburg, pp. 51.
Müller GJ. 1999. Management of bites and stings: controversial aspects. Abstract of the 6th African Arachnological Colloquium. African Arachnological Society Newsletter 12.
Croucamp W. 2000. Spider bites – diagnosis and management. Journal of Continued Medical Education. 18(8): 670-678.
Isbister GK, Gray MR. 2002. A prospective study of 750 spider bites, with expert spider identification. Queensland Journal of Medicine 95: 726–731.
Diaz JH. 2004. Global epidemiology, syndromic classification, management and prevention of spider bites. American Journal of Tropical Medicine and Hygiene. 71(2): 239–250.
Müller GJ. 2005. Management of venomous bites and stings: A mini-review. Unpublished notes.
Snyman C, Larsen N. 2005. Spider bite and its treatment in southern Africa. Occupational Health South Africa 11(2): 22-26.