Abstract
Introduction
Fishhook injuries are a common occurrence among anglers. There are no guidelines for prophylactic antibiotic use after fishhook removal. This study analyzed the management of embedded fishhooks, prophylactic antibiotic use, and complication rate at a Michigan county emergency department to observe whether antibiotic use changes patient outcome. Commentary on a freshwater pathogen (Aeromonas hydrophila) is also included.
Methods
Cases were obtained through a retrospective chart review of patients seen for fishhook injury between 2016 and 2022. We analyzed age, sex, relevant medical history, type of fishhook, site preparation, removal technique, antibiotic use, return visit within 30 days, and complications.
Results
Fifty-one patients with fishhooks injuries were identified. Mean age was 48±17 y. Forty-three patients were male (84%), and 8 were female (16%). Hook site varied, with most occurring in the finger/thumb (78.4%) and scalp (5.9%). One case involved the ear cartilage. The most common removal technique was the advance and cut method (52.9%). Four patients had an immunocompromising condition (eg, diabetes). Oral antibiotics were prescribed to 26 patients (51%) on discharge. Prophylactic antibiotic choice varied—cephalexin predominated (61.5%). There were no wound infections or complications in cases where the fishhook was removed during the emergency department encounter (50 of 51). One case involved a delayed presentation, abscess formation, and outpatient hand surgery referral.
Conclusions
In this small observational study, antibiotic prophylaxis for freshwater-associated fishhook injury did not change outcome regardless of fishhook location or presence of an immunocompromising condition. Further controlled studies are needed to determine the validity of these findings.
Introduction
The use of fishhooks, nets, and other tackle to obtain fish and aquatic creatures drops deep into the arc of human history. In modern times, angling for recreational purposes and food procurement has hooked many Americans as a popular outdoor activity. According to the 2022 National Survey of Fishing, Hunting, & Wildlife-Associated Recreation, it is estimated that 39.9 million US residents ages 16 y and older participated in fishing activities. US commerce around recreational fishing totaled $99.4 billion spent on licenses, permits, fishing and camping equipment, clothing, boats, automobiles, land leases, and ownership. Specifically, $8.9 billion was spent on rods, reels, depth finders, tackle boxes, artificial lures, flies, and other gear. Freshwater anglers predominated, numbering 35.1 million participants taking 359 million trips and floating 559 million days a field. 1 As with any outdoor pastime, there is measured risk involved with fishing. Anglers are exposed to the elements and various aquatic settings and handle sharp tackle with slippery fresh- and saltwater catch. The existing body of research on fishhook injuries focuses mainly on fishhook removal methods.2–5 Prophylactic systemic antibiotic use after fishhook removal remains controversial without formal recommendations or randomized trials to support or discourage their use.2,3,5–7 Clarity around appropriate antibiotic prophylaxis in fishhook injury could mitigate unnecessary prescriptions, reduce healthcare costs, lower potential side-effect risks to patients, and help prevent the development of antibiotic-resistant strains of bacteria. Literature reviewed details a limited set of case reports and series involving water-exposed puncture and traumatic injuries in which infections develop6,8–14—only one of which involved a fishhook puncture. 15 Other authors have queried the National Electronic Injury Surveillance System and estimate that <1% of fishhook injuries result in infection. 16 Our retrospective single-institution study aims to analyze the management of fishhook injury, determine the rate of prophylactic antibiotic use, and observe whether patient outcomes are different.
Methods
Cases were obtained through a retrospective chart review of the Henry Ford Jackson Hospital electronic medical records. Keywords and corresponding International Classification of Diseases, Tenth Revision (ICD-10) diagnosis codes included fishhook, fishhook injury, and fishing hook foreign body. The time period of the review ran from January 1, 2016, to July 1, 2022.
Inclusion criteria were age >18 y and a fishhook injury. Prisoners, pregnant patients, and those <18 y of age were excluded. Variables tracked included age, sex, immunocompromising condition (eg, insulin-dependent diabetes mellitus, non-insulin-dependent diabetes mellitus, peripheral arterial disease, rheumatologic diseases, and use of immunosuppressive medications), narrative of the injury, type of fishhook, wound-site preparation/cleansing, fishhook removal technique, antibiotic use, final disposition, return visit within 30 days, and complications (eg, post-removal wound infection, surgical debridement, and disability). The Henry Ford Jackson Hospital institutional review board approved the study. All analyses of the study data were performed using IBM SPSS Statistics, version 26 (IBM Corp, Armonk, NY). In comparing means across groups, the analysis-of-variation F test was used with a cutoff P value of 0.05 to determine statistical significance. Cross-tabulation was performed by comparing rates of infection across groups. Fisher's exact test was used with a cutoff P value of 0.05 to determine statistical significance. Data are reported as mean±SD.
Results
Fifty-one patients were identified in our data review. Forty-three were male (84%), and 8 (16%) were female. Patient age was 48±17 y.
Types of fishhooks recorded were single barb (n=37 of 51; 72.5%) and treble barb (n=14 of 51; 27.5%). Fishhook injury locations varied: finger/thumb (n=40 of 51; 78.4%), scalp (n=3 of 51; 5.9%), and hand (n=2 of 51; 3.9%). One case occurred in each of the following locations: arm, ear, face, foot, leg, and nose for a total of 6 of 51 (12%). Notably, a 26-y-old male presented with a fishhook in his ear cartilage—the hook was removed by the advance and cut method. The patient was discharged without prophylactic antibiotics and had no complications. There were no cases in which tendon or ocular involvement occurred.
Most charts did not document specific preparation of the fishhook injury site prior to removal. Wound care varied and included cleansing with soap and tap water, irrigation with normal saline, irrigation with dilute betadine, wiping with an alcohol swab, and scrubbing with chlorhexidine solution. The frequencies of fishhook removal techniques and descriptions are displayed in Table 1. Reasoning behind removal technique chosen was not discussed in the chart review. The most common removal technique was the advance and cut method (52.9%). Among fishhooks removed during the emergency department encounter (n=50 of 51), no complications were found on 30-d follow up.
Frequency of techniques used in fishhook removal.
The fishhook is grabbed with pliers and advanced through the skin, exposing the barb. The barb is cut off with wire cutters, and the barbless bend and shank are then removed via the original entry path.
A small incision is made overlying the barb; the fishhook is then pulled out through this incision.
A string is tied to the bend of the fishhook. Simultaneously, downward pressure is applied to the shank, and the string is swiftly pulled parallel to the shank, causing the barbed hook to disengage and exit the skin.
The bend of the fishhook is grasped with pliers, and downward pressure is applied to the shank. The hook is then backed out of the skin following the original entry path.
Except for 1 case, all fishhooks were removed prior to discharge. An otherwise healthy 77-y-old male presented with an embedded barb in his right thumb—he attempted self-extraction 3 weeks earlier, leaving only the barb buried in his thumb that appeared noninfected. The patient was discharged without antibiotics and hand surgery follow-up 1 wk later. The hand surgeon administered cephalexin 500 mg/d PO for 5 d and performed foreign-body removal in the office. The surgeon encountered a small pocket of purulence in the pulp of the thumb that was evacuated and irrigated; the 5-mm incision was left open to heal by secondary intention. Wound culture grew Streptococcus agalactiae (Group B) susceptible to penicillin, Morganella morganii, Klebsiella oxytoca, and Proteus vulgaris. On 2-wk follow-up, the patient had healed well. No other complications were identified regardless of prophylactic antibiotic use.
Oral antibiotics were prescribed to 26 of 51 patients (51%) discharged from the emergency department. Twenty-five patients (49%) did not receive antibiotics on discharge. The antibiotic group had a higher mean age (52±17 y) than the nonantibiotic group (44±16 y), but this was not statistically significant (P=0.092). Including the single aforementioned delayed presentation, there was no statistically significant difference in overall occurrence of infection based on antibiotic use at any point in the case (P=0.490).
Prophylactic antibiotic choice and duration varied—cephalexin accounted for 16 of 26 (61.5%) of the antibiotics prescribed (Table 2). No intravenous antibiotics were administered. Four patients (7.8%) were found to have a relevant medical history (Table 3). One was noted to have poorly controlled insulin-dependent diabetes mellitus. Three patients had non-insulin-dependent diabetes mellitus. Three of 4 patients (75%) with immunocompromising conditions received prophylactic antibiotics. None of these patients suffered a complication regardless of prophylactic antibiotic use or fishhook location.
Prophylactic oral antibiotics used for fishhook injuries.
Descriptions of patients with immunocompromising conditions.
DM1, diabetes mellitus type 1; DM2, diabetes mellitus type 2.
Discussion
Consistent with prior studies, most fishhook injuries occurred in the fingers, and the most common extraction method was the advance and cut technique.2,4,16–18 No intraprocedural or postprocedural complications were noted. With the exception of 1 delayed presentation, there were no instances of wound infection in either the antibiotic group or the nonantibiotic groups regardless of immunocompromising condition (4 cases) or cartilage involvement (1 case). This begs the question, “Are prophylactic systemic antibiotics necessary for fishhook injuries?”
Simple uncontaminated soft tissue wounds and lacerations in otherwise healthy patients do not require prophylactic systemic antibiotics.17,19 Fishhook injuries differ because they are puncture wounds and often involve an embedded foreign body for a period of time. Additionally, injured anglers are exposed to fresh, brackish, or salt water and are handling fish—all of which contain various microorganisms that can be pathogenic to humans. All cases recorded in our study occurred locally in the freshwater bodies of southeastern Michigan, and thus our discussion is limited to fresh water.
Aeromonas hydrophila
One such freshwater bacterium of interest is Aeromonas hydrophila. As the Linnaean taxonomy implies, A hydrophila (“water lover”) is found in freshwater and soil. Concentrations vary with organic pollution and environmental conditions. Multiple case reports exist on the pathogenicity of this anaerobic facultative gram-negative bacillus in traumatic soft tissue injuries.6,8,9,15 These cases involved traumatic skin and soft tissue injuries with freshwater exposure: a thumb laceration from a freshwater fish dorsal fin, knee laceration exposed to drainage ditch water, foot laceration in a freshwater lake, crocodile bite involving the buttock, a boating accident resulting in a crush injury to the lower leg, and a scalp laceration sustained while diving into a creek.8,9,14,15 We found a single case report specifically involving a fishhook puncture to the forearm of a male that resulted in an abscess that cultured A hydrophila. 15
While the incidence of soft tissue infection with A hydrophila is low, the significant damage that can occur warrants understanding this pathogen because patients may require prolonged courses of antibiotics, multiple tissue debridements, skin grafts, and possible amputations. 9 Aeromonas bacteria produce extracellular cytotoxins and hemolysins that are responsible for severe tissue damage and can result in liquefaction of muscle. Soft tissue infections associated with this bacteria have been categorized into 3 groups: acute cellulitis limited to the dermal layers of skin, necrotizing soft tissue infection, and ecthyma gangrenosum, which is associated with immunocompromising conditions (eg, liver cirrhosis, diabetes mellitus, peripheral vascular disease, and cancer). Ecthyma gangrenosum is characterized by an ulcerative pyoderma with hemorrhagic and inflammatory bullae. 15
Fishhook injury and antibiotics
A literature search revealed no guidelines or controlled trials on prophylactic antibiotic use in fishhook injuries. One author stated, “Well conducted, controlled studies do not exist that support the need for systemic antibiotics in these cases; they are generally not indicated.” 3 A PubMed query revealed only 2 studies that detail antibiotic use in fishhook injuries and complication rates.17,18 A prospective analysis of 95 fishhook injury patients in Soldotna, Alaska, found no complication or wound infection in any patient regardless of systemic antibiotic use. Notably, in that study, only 4 patients received oral antibiotics, including 2 patients who had fishhooks embedded in pinna cartilage and a forearm tendon. 17 Another retrospective study of 165 fishhook injuries in eastern Newfoundland, Canada, found no instances of post-removal wound infection—however, 94 of 165 patients (57%) received oral antibiotics, 18 of 165 (10.9%) received topical antibiotics, and 3 of 165 (1.8%) received intravenous antibiotics before discharge. These latter results are confounded by high rates of antibiotic use. Even so, both authors stated that systemic antibiotics for uncomplicated fishhook injuries may be unnecessary.17,18 Although our dataset included inland freshwater injuries only, both of these prior studies occurred in coastal environments. Although no details on water type were included in the aforementioned studies, they do mention specific salmon and halibut tackle, indicating salt and brackish waters were likely encountered by some anglers in their dataset. Similar to these larger studies, we found no instances of wound infection in patients with emergency department fishhook extraction regardless of antibiotic prophylaxis.
The infectious disease, emergency medicine, and trauma literature reviewed recommended treatment of infections resulting from freshwater exposure with either fluoroquinolones or a combination of an aminoglycoside (eg, gentamicin, tobramycin, or amikacin) and an extended-spectrum cephalosporin (eg, cefotaxime or ceftazidime).6,8,15 One source stated, “Empiric ciprofloxacin should be considered for such infections, but even prompt use of antibiotics may not obviate the need for surgical intervention.” However, there is no evidence cited for this recommendation. 15 Another paper commented on freshwater injuries, “The benefit of prophylactic antimicrobials following initial wound care is likewise unproven.” 6 Multiple authors advise that systemic antibiotics should be considered for water-exposed cases that involve devitalized tissue, gross contamination, deep tissue involvement, and immunocompromised hosts.3–5,14,15,20 Although these cited authors do not specifically address prophylactic antibiotics in fishhook injuries, most state that fastidious local wound care is paramount in preventing infection for water-exposed cases.3,5,11,15,20
Limitations
Study limitations include the retrospective design, incomplete medical documentation (eg, specification of tendon/cartilage involvement or use of topical antibiotics after fishhook removal), small sample size, exclusion of patients <18 y of age, injuries occurring in the inland freshwater of southeastern Michigan only, and variations in local wound care before and after fishhook removal. There is a probable reporting/identification bias—patients with more serious injuries (eg, retained fishhooks) are more apt to seek medical care. Patients who removed the hook themselves may not have presented for evaluation. Some patients may have presented to outside institutions if an adverse event occurred, thereby limiting follow-up.
Conclusions
Inappropriate use of antibiotics may not reduce the risk of infection, can cause harm, and may promote the development of resistant strains of bacteria.21,22 Prophylaxis of any kind must balance risk versus benefit—antibiotics are no exception. Our dataset showed no complication from fishhook extraction in the emergency department regardless of prophylactic antibiotic use, relevant immune history, or location of tissue injury. These conclusions should be tempered by our small sample size and geography because all cases occurred in the fresh waters of the lower peninsula of Michigan. These results may not be generalizable to all environments or bodies of water. Prophylactic oral antibiotic choice varied—cephalexin predominated, with a few patients receiving alternative freshwater pathogen coverage. This study and the with other limited observational research cited suggest that the routine use of prophylactic antibiotics for simple fishhook injuries may be unnecessary because the rate of resulting infections is very low.7,16–18 Antibiotics should be considered in select cases based on initial presentation, relevant medical history, and length of foreign-body retention. Controlled studies on fishhook injuries occurring in various types of water (eg, salt, brackish, fast moving, and stagnant) are recommended to determine the validity of these results. Further research on the topic would benefit the outdoor community and healthcare providers, informing when and what class of antibiotics are needed, if any.
Footnotes
Acknowledgments
The authors are grateful to Ryan Madden, who served as our entrusted librarian, and to David Metcalf and Candi Bachour, who provided statistical analysis and study guidance.
Author Contribution(s)
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
