THE JOURNAL OF FAMILY ONLINE EXCLUSIVE PRACTICE Paul K. Carlton, Jr, MD, Brown recluse spider bite? FACS The Texas A&M University Consider this uniquely Health Science Center College Station, Tex conservative treatment [email protected] An antihistamine and observation work as well— and often better—than more intensive therapies. Practice recommendations oped it in 4 phases, which I describe in • Be concerned about brown recluse this article. Not only does this conser- envenomation when a patient vative approach consistently heal con- reports intensifying localized firmed brown recluse bite wounds, but pain disproportionate to physical should a bite be mistakenly attributed findings after a “bite” (C). to the brown recluse (or one of its rela- tives in the Loxosceles genus of spider), • Prescribe an oral antihistamine there is no harm to the patient, nor any alone to control symptoms, even big expense. with a necrotic wound, and mark the IN THIS ARTICLE patient’s progress over 24 hours (C). z Spider bite z Is a brown recluse • If the patient improves dramatically, to blame? or MRSA? continue the antihistamine; with little Due to limited experience among the Page E6 or no improvement, consider giving an wider medical community in identifying antibiotic with the antihistamine (C). spider envenomation,1-4 bite recognition and selection of appropriate therapy can Strength of recommendation (SOR) be difficult. A Good-quality patient-oriented evidence Early findings can be confusing. B Inconsistent or limited-quality patient-oriented evidence C Consensus, usual practice, opinion, disease-oriented Brown recluse bites typically feel like a evidence, case series pin prick. A vasoconstrictive halo may surround the bite, but this sign is in- consistent. Usually there is nothing to hat is the best way to treat the see immediately and pain from the bite bite of a brown recluse spider? goes away, so most patients dismiss the WHaving treated more than 185 incident.5 Soon, however, pain from the bite wounds on 150 patients over the envenomation begins and, importantly, past 30 years, I have found that an oral becomes disproportionate to physical antihistamine works best and makes sur- findings—the patient shows you where gery unnecessary. it hurts, but there is nothing visible to I did not arrive at this treatment support a diagnosis or suggest a course protocol immediately but, rather, devel- of action. C O NTIN UE D www.jfponline.com VOL 58, NO 2 / FEBRUARY 2009 E THE JOURNAL OF FAMILY PRACTICE FIGURE 1 z How my treatment The distinctive “fiddle” mark protocol evolved My protocol for treating necrotic bite wounds of the brown recluse, and similar wounds from other insects, progressed over 30 years through 4 phases of treat- ment concepts. Phase : Surgical excision From 1979 to 1980, I treated necrotic wounds with surgical excision and sec- 1 The brown recluse spider has a distinctive “fiddle” mark ondary closure or skin grafting. Many on the back of its thorax. unfortunately, though, intact patients complained of severe itching specimens are seldom available for examination after a bite. rely instead on the natural history of the wound in around these wounds, which I treated attributing a bite to the brown recluse. empirically with the antihistamine Bena- dryl. All patients experienced symptom Progression of the wound usually tells relief and had a reasonable cosmetic re- more than a captured specimen. If you are sult (FIGURE ). fortunate enough to examine an intact In writing up the case results for a spider caught by the patient, a “fiddle” presentation to the Society of Air Force mark on the spider’s back confirms it is a Clinical Surgeons, I conducted back- brown recluse (FIGURE ). However, most ground research and found a postulate specimens brought in for examination are suggesting that antigen recognition was so misshapen from the patient’s retribu- an important factor in wound progres- tion as to make identification futile. I fo- sion and that it took approximately cus instead on the resultant wound. 7 days to achieve. That postulate drove Spider’s venom causes the wound. Spi- the second phase of discovery.1 FAST TRACK ders lack a mechanical digestive system; A wound with a their so-called venom actually is a set of Phase : enzymes that liquefy a prey’s tissues.6 In Observation before debridement large underlying the 48 hours after a bite, these digestive From 1980 to 1981, I focused on the cavity and small enzymes cause a progressive necrosis of postulate, which also suggested that the area of skin fat under the skin. Eventually the overly- antigen–antibody reaction following en- necrosis is a ing skin also turns necrotic. The venom venomation could make reactions to sub- does not penetrate underlying fascia sequent (“second set”) bites less severe.1 likely insect bite. planes, as many infectious processes do. This made sense, though good clinical Necrosis can, rarely, cause dissemi- data were lacking. nated intravascular coagulation and I decided to simply observe patients’ S death. A more likely scenario, though still wounds for 7 to 10 days before perform- C A f , relatively uncommon, is that the necrotic ing debridement, advising patients to use D M sequence leads to an indolent wound that an antihistamine to control symptoms JR, , N heals only with difficulty. Most patients during the waiting period. I took photo- O T recover without medical care and do not graphs to document clinical progression ARL 7-9 c K. even seek it. of wounds. In reviewing these photo- Wounds can be categorized, as graphs, I noted that the necrotic wounds AUL f p f 10 O outlined by Auer et al, into groups 1 stabilized immediately on starting an ESY through 4, from least severe to most se- antihistamine—specifically, Benadryl, T vere. However, this classification scheme 5 mg/kg or 50 mg qid. After 7 to 10 days, OUR c OS has made no difference in my manage- I debrided the wounds, using fluorescein T HO ment decisions. and a Woods lamp to guide the proce- P E VOL 58, NO 2 / FEBRUARY 2009 THE JOURNAL OF FaMILY PRactIce Brown recluse spider bite? t FIGURE 2 Bite wound treatment: Debridement and closure or skin grafting A B C One day following the bite, this 17-year-old boy’s Fully debrided, the wound was ready for skin This skin graft, taken from the groin, healed sat- wound was clearly necrotic. grafting. isfactorily in 4 weeks. Patients often complained of severe itching around the wound, which was relieved with benadryl. dure. I found that tissue of doubtful vi- other insects. None have required oper- ability survived if debridement was con- ative debridement, and all have achieved servative and the patient had used an much more acceptable cosmetic results antihistamine (FIGURE ). using Benadryl therapy than with surgi- cal therapy. Phase : My encounter with a brown recluse. Focus shifts from surgery The bite I received was rather typical. I to antihistamine felt a sharp sting when outside working In reviewing phase 2 results in prepara- on the lawn. I looked down, saw noth- tion for a presentation to the Southwest- ing, and assumed I had run into a pin ern Surgical Congress, I realized that or small stick that was now not visible. debridement was rarely indicated. So, For 3 days I noticed nothing unusual. from 1981 to 1982, I relied less on sur- On day 4, after showering I noticed a FAST TRACK gery and more on conservative therapy. large amount of purulent material on I noted that Patients got better simply with antihis- the towel after drying my anterior left tamine therapy. Redness diminished very leg. On inspecting the area, I saw an necrotic bite quickly once patients took the antihista- area of necrosis approximately 6 x 6 wounds stabilized mine, and pockets of purulent material cm with a central area oozing a puru- immediately drained on their own. lent material. This appeared just like after giving an This approach also allowed antigen the necrotic insect bites I had treated recognition to occur and seemed to prove with antihistamines, so I started myself antihistamine the postulate of a less severe second bite. on that regimen. The redness cleared up and improved I saw 4 patients with proven “second in 2 days and the wound healed com- dramatically in set” spider bites (intact specimens were pletely in 10 days without antibiotics. available) and all had an immediate in- A 3 x 3 mm circular scar remained; I 24 hours. flammatory response and no subsequent lost none of the surrounding marginal necrosis. An 18-month-old patient with skin. a bite below her right eye healed with Further evidence of less severe second Benadryl therapy alone (FIGURE 4). bites. Another physician—my coauthor on the presentation to the Southwestern Phase 4: Surgical Congress—was bitten at age 12 Exclusive antihistamine therapy by an unidentified insect, resulting in a Since 1982, I have treated more than large necrotic wound on his thigh. The 100 patients (myself included) with lesion, reportedly 10 to 12 cm in diam- necrotic bite wounds from spiders and eter, healed with topical treatment only. C O NTIN UE D www.jfponline.com VOL 58, NO 2 / FEBRUARY 2009 E THE JOURNAL OF FAMILY PRACTICE FIGURE 3 Bite wound treatment: Observation for 7 to 0 days A B C The bite wound on this 52-year-old woman was At day 5, the wound had grown, but there was On day 7, I performed a sharp excision of only the 3 days old when this photo was taken. I observed minimal necrosis. nonfluorescing area, as shown. the wound’s progression without debridement to allow time for adequate antibody response.