A 60-year-old woman presented to the surgery oncology clinic with a necrotic lesion on the inferior lateral portion of her left breast. The patient said 2 weeks ago, she noticed a small pustule on her left breast and thought that she may have been bitten by a spider while she slept. She placed spider traps in two bathrooms in her house and under her bed, and caught spiders resembling the brown recluse (Loxosceles reclusa, Figure 1) in the trap under her bed and in the bathroom attached to her bedroom. Her primary care provider initially prescribed trimethoprim/sulfamethoxazole for what was thought to be a skin infection. Over the following 2 weeks the lesion developed ecchymosis (Figure 2) that progressed to a black area of necrotic tissue (Figure 3). Despite antibiotic treatment, the erythema and necrosis continued to spread. On a follow-up visit, the patient was prescribed ciprofloxacin and referred to a surgeon. Her medical history was positive for hypertension, asthma, and hypothyroidism.
Physical examination The patient's vital signs on presentation were: BP, 166/84 mm Hg; heart rate, 78 beats/minute; and temperature, 98.8° F (37.1° C) orally. The examination revealed 15 cm by 5 cm eschar on the patient's left inferior lateral breast with a 5 cm area of blanching erythema extending beyond the eschar margins. No axillary, infraclavicular, supraclavicular, or cervical lymphadenopathies were noted. Radial pulses were 2+ and equal bilaterally. The cardiovascular, respiratory, and abdominal examinations were within normal limits.
Initial treatment The patient was taken to the OR for excision and debridement of the affected area. The lateral area around the eschar expressed purulent drainage that was sent for culture and sensitivity. Culture reports revealed mixed flora. An elliptical incision was made around the eschar. The depth of the excision extended until normal breast tissue was reached. A 15 cm by 9 cm section of tissue was removed and sent to pathology. Pulsatile lavage with 2 L of normal saline and antibiotic irrigation were applied after the necrotic tissue was excised. The wound was left open (Figure 4) and negative-pressure wound therapy was applied the next morning. Negative-pressure wound therapy can decrease time in the hospital, promote granulation tissue formation, and decrease dressing changes. The patient was started on clindamycin 600 mg IV every 6 hours while in the hospital and was switched to oral clindamycin upon discharge the following day.
At 8 days status postop, the patient returned to the clinic for a follow-up. The negative-pressure wound therapy was removed and the previous skin erythema and inflammation had greatly improved. A delayed primary closure was performed in the office, and the wound was packed with iodoform. Sutures were removed 21 days status postop (2 weeks after delayed primary closure). A 1 cm by 1 cm lesion remained open and healed without complication on its own (Figure 5).
Brown recluse spiders are one of two types of spiders in the United States that can cause significant tissue damage and, rarely, death.1 Black widow bites can cause severe muscle spasms and rigidity within 30 minutes to 2 hours of a bite.2
The brown recluse spider is predominantly found in the South Central region of the United States, from Nebraska to Ohio in the Midwest and from Georgia to Texas in the South.3 These spiders live in dark, warm habitats such as woodpiles, barns, clothing, and bedding. Bites occur most often in May through August, and when people are lying in bed or putting on shoes or clothing in which the spider has hidden.4
The brown recluse can be identified by a fiddle-shaped marking on its back.3 The body of the fiddle starts at the spider's head.
The most common presentation of a brown recluse spider bite includes pruritus, pain, erythema, and pustule formation.1,3 In 10% to 15% of patients, these symptoms progress to more serious complications that include scarring, hospitalization, or chronic lesions.3 Brown recluse spider venom can trigger cell membrane destruction and an inflammatory immune response, leading to tissue necrosis.1 Factors that predict rapidly healing wounds include low severity, less erythema and necrosis at the time of patient presentation, younger patient age, lack of diabetes, and early medical care.5
The only conclusive way to diagnose a brown recluse spider bite is to see and identify a captured spider. A complete patient history and physical can help clinicians rule out more common causes of necrotic skin lesions, such as bacterial and fungal infections, diabetic ulcers, and pressure ulcers.1
The treatment of brown recluse spider bites remains controversial, but the treatment goals remain the same: maintain skin integrity, prevent infection, and preserve circulation.1 Because most bites do not cause serious complications, conservative treatment is appropriate. For the first 72 hours, rest, ice, compression, and elevation (RICE) of the affected area can reduce tissue damage.1,3 Medical management with nonsteroidal anti-inflammatory drugs for pain relief and inflammation, antibiotics for cellulitis, and tetanus prophylaxis may be required.1
Dapsone has been shown to decrease the need for tissue excision by inhibiting neutrophil function.1 Treating brown recluse spider bites with dapsone significantly reduces the need for surgical intervention.6 However, dapsone use has been limited because of its adverse reactions, including hemolysis, sore throat, pallor, agranlocytosis, aplastic anemia, cholestatic jaundice, methemoglobinemia, peripheral neuropathy, and hyperbilirubinemia.7 Because of the risk for hemolysis, dapsone cannot be used in patients with glucose-6-dehydrogenase deficiency.7
Hyperbaric oxygen therapy has been used to treat brown recluse bite wounds, although its effectiveness is controversial. This therapy promotes angiogenesis, decreases envenomation, and decreases inflammation.3 Angiogenesis can help promote healing and decrease the severity of the lesion.3 Hyperbaric oxygen affects the chemical structure of venom, deactivating it, and may cause pulmonary sequestration of polymorphonuclear lymphocytes, helping to reduce inflammation.2,3
Most bites are not serious and do not require surgical treatment, but for those that do require surgical intervention, delayed treatment may be best. With early surgery, the lesion may not be well-defined, increasing the likelihood of a secondary surgery because the lesion may continue to spread for up to 2 weeks.3,7 Delayed surgical excision of a mature eschar can decrease the risk of delayed wound healing, abscess formation, and scarring.6
Negative-pressure wound therapy promotes healing in necrotic wounds caused by brown recluse bites.8 The primary mechanism of action is to draw the wound edges together, stabilize the wound environment, decrease wound edema, and remove exudate.9 This therapy also increases angiogenesis and granulation tissue formation, and decreases bacterial colonization.9
Brown recluse spider bites usually can be managed with conservative treatment including rest, ice, compression, and elevation. Patients with a severe bite will often present with signs of local skin infection and eschar. Treatment for these patients depends on the amount of time that has elapsed since the bite and the location and size of the lesion.
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4. Vetter RS. Seasonality of brown recluse spiders, Loxosceles reclusa
, submitted by the general public: implications for physicians regarding loxoscelism diagnoses. Toxicon
5. Mold JW, Thompson DM. Management of brown recluse spider bites in primary care. J Am Board Fam Pract
6. Rees RS, Altenbern DP, Lynch JB, King LE Jr. Brown recluse spider bites. A comparison of early surgical excision versus dapsone and delayed surgical excision. Ann Surg
7. Nunnelee JD. Brown recluse spider bites: a case report. J Perianesth Nurs
8. Chariker M, Ford R, Rasmussen E, Schotter E. Management of periauricular and auricular necrotizing wound from brown recluse spider bite using negative pressure wound therapy and wound interface modulation. Eplasty
9. Orgill DP, Manders EK, Sumpio BE, et al. The mechanisms of action of vacuum assisted closure: more to learn. Surgery
© 2014 American Academy of Physician Assistants.