March 2009 - Volume 3, Issue 2

Brown Recluse Spider Bites; A Case Report

	Dr Ebtisam Elghblawi, MBBCh, MSc, Bir
	Usta Milad Dermatology Hospital Tripoli-Libya. E-mail: ebtisamya@yahoo.com

ABSTRACT Spider bite is a special skin incident encountered. However there are more than 100,000 species of spiders, but most of them are not dangerous due to their delicate mouthparts, and if they bite, they cause local irritation, redness with swelling, pain, and itching which can last from a few hours to a few days. Those symptoms can be treated by over-the counter analgesics and antihistamines. Systemic symptoms are unusual. However, severe envenomations by the black widow variant are associated with involuntary muscular spasm, diaphoresis, and hypertension, which can be mistaken for an acute abdomen or myocardial infarction. Key Words: Spider bite, Brown recluse spider, envenomation, tissue necrosis, necrotic arachnidism, skin necrosis, spiders

CASE REPORT:

A young healthy 36 year-old, white Libyan lady, five months pregnant (G2, P1+0) presented over the course of two days to the OPD with a wound lesion characteristic of a necrotic brown recluse spider bite, which had arisen accidentally when she woke-up in the morning. She presented complaining of pain, severe itching and swelling since two days. She came to us on the 4th day of her illness. Clinically the lesion was located on her lower right leg on the anterior ankle area and dorsal aspect of the right foot (as can be seen in Figure1), about 5 x 7 cm, with a central bluish-purple discolouration, and had three ulcerations at the base of the lesion, surrounded by an erythematous border, and swelling, O/E; hot and tender on palpation, associated with some fluid oozing. Patient does not have any chronic ailments.

Investigations requested were complete blood picture, liver function test, kidney function test, and routine urine analysis, and all were within normal range.

Patient came after a week for the first follow up, and she was much better as the lesion started to subside and close up gradually. Also the swelling decreased slightly; however the patient was still not satisfied and wanted a speedy recovery.

BACKGROUND

There are more than 100,000 genuses of spiders, but two notable exceptions worth mentioning; are the black widow spider (Latrodectus species), and the brown recluse spider (Loxosceles species). Most spiders are not dangerous to humans and do not require a spider bite treatment, but can be deleterious to babies, children and elderly due to their venom (toxin) when injected at the bite site 1. The black spider is a small dark black spider with a red hourglass mark on its belly, and found frequently in low-lying webs in garages, around swimming pools, and in wood piles and their bite occurs between April and October defensively, and is more venomous 2, while the brown spider is a long spider with a violin mark on its upper back, and lives in hot, dry abandoned areas such as woods, rocks and bed linen. A bite from a widow spider (mostly female black widow) results in sharp pain followed by swelling and erythema at the site of bite, which is characterised by two small fang marks at the bite site, then muscle spasms and rigidity starting at the bite site within 30 minutes to two hours, with chills, fever, and acute abdomen pain. While the brown recluse bites occur early in the morning because it is only active at night 3, and its bite is painless, it won't be noticed at the start by the patient, but then a red skin area develops followed by a blister at the bite site, then pain with itching occurs for 2-8 hours post bite. These bites usually progress to ulcerating dermo-necrosis at the bite site within a few hours (Necrotic arachnidism) with necrosis which takes months to heal 2,3. Some generalised symptoms might be seen due to systemic reactions such as haemolytic anaemia fever, chills, and joint pain.

Usually a spider bite victim is unaware of the bite until some hours later. Spiders can cause severe envenoming, with either neurotoxic effects or necrotic ulcers 3. Though spider bites can produce necrotic skin lesion, the differential diagnosis of such lesions is extensive; mostly Community-Acquired Methicillin-Resistant Staphylococcus aureus; CA-MRSA, pyoderma gangrenosum, cutaneous anthrax and many more 4.

Treatment is usually supportive; washing the site with water and soap, ice pack, elevation of the affected part to minimise inflammation and swelling, analgesics for the pain and antihistamine for the itching, and complete avoidance of any strenuous work. Any debridement or local steroid injection is forbidden completely as it might extend the extent of dermo-necrosis.

DISCUSSION

The patient gave a classical history of spider bite, as she hadn't noticed, felt, or realised that she had been bitten in the first place, and that is well-documented in the literature that the spider is seldom ever seen by the patient. Ulcerating lesions of unclear aetiology always raise the suspicion of a spider bite. Diagnosis is made based on patient description and on clinical examination. Our patient woke-up in the morning and noticed her right foot was swelling, and associated with pain and severe itching though she slept in the night before and was perfectly fine. During these few days before she sought a medical consultation, she applied some local steroid ointment, but without any improvement. Patient did not give history of bulla formation, and this can be attributed to the associated severe itching and scratching. The ulcerative lesion over her right foot developed within the first two days, and can be explained to be the site of the bite by the spider as can be seen in the Figure-1 (double fang mark).The Brown recluse is the finest-known species of spiders belonging to the genus Loxosceles. These spiders are well-known because of their characteristic markings. They have a dark, violin-shaped marking on the cephalo-thorax part. They are also referred to as "fiddle back" spiders. Research speculated these spider's venom is responsible for the patho-physiological features of the bite (necrotic ulcer). When the spider bites, it injects cytotoxic venom, which is composed of many potent enzymes; alkaline phosphatase, 5-ribonucleotide phosphohydrolase, lipase, protease, esterase, hyaluronidase, and the most important and active enzyme is sphingo-myelinase-D which was postulated a long time ago by Forrester et al in 1978. It was believed that sphingo-mylinase enzyme was the sole cause for haemolysis, plus cutaneous and systemic reactions, as was explored by Forrester et al5. Later on, this venom was projected to be the cause the dermo-necrosis by Patel et al. (1994)6. This was explained by initiating a reaction in the vascular endothelium, which would attract the neutrophil, and later would attach to endothelium and induce a reaction by releasing its granules. This mechanism starts by inducing the release of E-selectin, which causes release of cytokines; namely interleukin-8 and granulocyte macrophage colony-stimulating factor, both of which act as key mediators in the attraction and activation of neutrophils, whereby the neutrophils bind to E-selectin, then degranulate and cause tissue destruction. Our case illustrated a minimal route of cutaneous loxoscelism (skin necrosis), and that can be explained because the affected location has few fat cells.

A literature review indicates and assures that the brown recluse spider bite is a frequent and sometimes can serious clinical entity 7. Furthermore literature review acknowledged only a few reported cases of loxoscelism involving the dorsum of a foot as our case is. Those cases mentioned in the literature illustrated lesions consistent with bites caused by the bite of a Brown recluse spider, but none supplied definitive proof for the causation by the brown recluse spider.

Each case expresses early morning swelling, with redness and pain leading to significant oedema without noticing the spider at the first place 8. The lesions became necrotic in the first day, formed black eschar and resulted in some degree of scarring when healed. All cases passed through similar stages and within the same time. Later on the outcomes were satisfactory to each affected case.

Management decisions stipulate cautious consideration of exact location of the bite, degree of envenomation, age and general circumstances of the patient's health. Though Anderson & Wasserman, noted in 1997 the infrequency of severe systemic reactions 9,10, Wilson and King indicated in 1990 that complications occur more frequently with bites to the eyelids, hands and feet11. Conservative approach was suggested as there is no observed support for various treatment modalities 12. The old modality of treatment involved dapsone, topical nitroglycerin and hyperbaric oxygen, as dapsone was thought to limit tissue destruction by the suppression of neutrophils but evidence supporting their use is lacking 12. Furthermore a current controlled study using New Zealand white rabbits failed to indicate benefit of either of these modalities 14,15.

An additional area of research involves the use of anti-venom. Rees et al. reported the benefit of administrating anti-venom in limiting the extent of dermo-necrosis if it was given within the first 24 hours 16. Regrettably anti-venom is not readily accessible and must be administered early following injury.

Although the management of this case is not presented as a therapeutic model, we believe the potentially dangerous location of the bite and the severe clinical presentation justified aggressive treatment, because they are available, and can be administered in a cautiously controlled scenery. To conclude it is always impossible to foresee what the clinical outcome would be, but in our case we approached her more conservatively17.

Lastly to the best of our knowledge, no such case report has been reported yet in the literature, and this would add it to the literature.

REFERENCES

1. Jacqueline Rhoads, Epidemiology of the brown recluse spider bite, Journal of the American Academy of Nurse Practitioners, (2006), Volume 19 Issue 2, Pages 79 - 85
   
2. P Dyachenko, Epidemiological and clinical manifestations of patients hospitalized with brown recluse spider bite, Journal of the European Academy of Dermatology and Venereology, (2005), Volume 20 Issue 9, Pages 1121 - 1125
   
3. James H. Diaz, Kim E. Leblanc, Common Spider Bites, American Family Physician, (2007), Vol. 75, No. 6
   
4. Tamara J. Dominguez, It's Not a Spider Bite, It's Community-Acquired Methicillin-Resistant Staphylococcus aureus, The Journal of the American Board of Family Practice( 2004), 17: 220-226
   
5. L.J. Forrester, J.T. Barrett and B.J. Campbell, Red blood cell lysis induced by the venom of the Brown recluse spider: the role of sphingomyelinase D, Arch Biochem Biophys (1978), 187 pp. 355-365
   
6. K.D. Patel, V. Modur and G.A. Zimmerman et al., The necrotic venom of the Brown recluse spider induces deregulated endothelial cell-dependent neutrophil activation. Differential induction of GM-CSF, IL-8, and E-selectin expression, J Clin Invest (1994), 94 pp. 631-642
   
7. Young, V Leroy, Pin, Paul, The Brown Recluse Spider Bite, Annals of Plastic Surgery. (1988), 20(5):447-452.
   
8. G.K. Isbister and M.R. Gray, A prospective study of 750 definite spider bites, with expert spider identification, 2002, Q J Med (2002); 95: 723-731
   
9. G.S. Wasserman and P.C. Anderson, Loxoscelism and necrotic arachnidism [review], J Toxicol Clin Toxicol 21 (1983-1984), pp. 451-472.
   
10. P.C. Anderson, Spider bites in the United States, Dermatol Clin 15 (1997), pp. 307-311
    
11. D.C. Wilson and L.E. King Jr., Spiders and spider bites, Dermatol Clin 8 (1990), pp. 277-286
    
12. S.W. Wright, K.D. Wrenn, L. Murray and D. Seger, Clinical presentation and outcome of Brown recluse spider bite, Ann Emerg Med 30 (1997), pp. 28-32.
    
13. M. Strain, T.G. Snider, B.L. Tedford and G.H. Cohn, Hyperbaric oxygen effects on Brown recluse spider (Loxosceles reclusa) envenomation in rabbits, Toxicon 29 (1991), pp. 989-996
    
14. S. Phillips, M. Kohn and D. Baker et al., Therapy of Brown recluse spider envenomation: a controlled trial of hyperbaric oxygen, dapsone, and cyproheptadine, Ann Emerg Med 25 (1995), pp. 363-368
    
15. A.Z. Bhatt, , A. Adeniran, S. Salam, M.A. Naveed and A. Phillips, Brown recluse spider bite to the leg, CASE REPORT, Elsevier Ltd , Volume 37, Issue 2, February (2006), Pages 45-48
    
16. R. Rees, R.B. Shack and E. Withers et al., Management of the Brown recluse spider bite, Plast Reconstr Surg 68 (1981), pp. 768-773
    
17. Wright SW, Wrenn KD, Murray L, Seger D., Clinical presentation and outcome of brown recluse spider bite., Ann Emerg Med. (1997);30(1):28-32