AGGRESSIVE OSTEOMEYLITIS OF TRAPEZOID FOLLOWING A PET CAT BITE

Abstract

The number of domestic animal bites is on an uptrend, but the numbers are underestimated as not all patients visit hospitals to seek treatment [Lee KJ et al. Domestic dog and cat bites: Epidemiology and analysis of 823 cases over the last 5 years. J Wound Manag Res 15(2): 68-77, 2019]. Among all bites, bites to the extremities such as hands and fingers have a higher rate of infection than elsewhere in the body due to superficial structures and high vascularity, which can aid the rapid spread of the infection [Lim JS, Byun JH, Min KH, Lee HK, Choi YS. Osteomyelitis following domestic animal bites to the hand: Two case reports and practical guidelines. Arch Plast Surg 43(6): 590–594, 2016]. The general perception of the public about pet animal bite is that wounds that are larger and have extensive tissue involvement are dangerous, while meager puncture wounds or scratches are harmless [Kim JWK, Kim JY, Kim UG, Kang DH, Kim DS, Kim JD. Treatment of phalangeal osteomyelitis caused by a cat bite. Clin Case Reports 9(10): 1–10, 2021]. In contrast, a small penetrating puncture injury by a pet is often considered harmless and is not treated properly, which eventually requires surgical procedure and results in permanent functional impairment for the patient [Lim JS, Byun JH, Min KH, Lee HK, Choi YS. Osteomyelitis following domestic animal bites to the hand: Two case reports and practical guidelines. Arch Plast Surg 43(6): 590–594, 2016]. Animal bites to the extremities, particularly the hands and fingers are commonly encountered as they are the most exposed parts of the body. Such bites can result in inflammation of the tendon sheath, septic arthritis, and in some cases, osteomyelitis, depending on the depth of the bite [Lim JS, Byun JH, Min KH, Lee HK, Choi YS. Osteomyelitis following domestic animal bites to the hand: Two case reports and practical guidelines. Arch Plast Surg 43(6): 590–594, 2016]. Dog bites usually do not reach up to bone-deep, while cat bites tend to cause deep, penetrating wounds due to their sharp needle-like teeth, which can pierce joint capsules and inoculate oral flora deeper into joint capsule and periosteum [Lee KJ et al. Domestic dog and cat bites: Epidemiology and analysis of 823 cases over the last 5 years. J Wound Manag Res 15(2): 68–77, 2019; Kim JWK, Kim JY, Kim UG, Kang DH, Kim DS, Kim JD. Treatment of phalangeal osteomyelitis caused by a cat bite. Clin Case Reports 9(10): 1–10, 2021; Elcock KL, Reid J, Moncayo-Nieto OL, Rust PA. Biting the hand that feeds you: Management of human and animal bites. Injury 53(2): 227–236, 2022, https://doi.org/10.1016/j.injury.2021.11.045 ]. Conversely, dog bites are more destructive causing large wounds that drain freely [Lim JS, Byun JH, Min KH, Lee HK, Choi YS. Osteomyelitis following domestic animal bites to the hand: Two case reports and practical guidelines. Arch Plast Surg 43(6): 590–594, 2016]. This is one of the most important reasons why cat bites are more harmful than dog bites. Pasteurella multocida, a small Gram-negative coccobacillus, is an oral commensal in many domestic animals, particularly dogs (isolated in 50–60% of cultures) and cats (isolated in 70–90% of cultures) harbor a higher proportionate of this organism in their oral cavity [Chodakewitz J, Bia FJ. Septic arthritis and osteomyelitis from a cat bite. Yale J Biol Med 61(6): 513–518, 1988]. Human infections with P. multocida are commonly encountered following animal bites or scratches [Kim JWK, Kim JY, Kim UG, Kang DH, Kim DS, Kim JD. Treatment of phalangeal osteomyelitis caused by a cat bite. Clin Case Reports 9(10): 1–10, 2021]. However, these can also occur in the absence of trauma in cases where the animal’s secretions come in contact with a wound or mucous membrane of an individual [Elcock KL, Reid J, Moncayo-Nieto OL, Rust PA. Biting the hand that feeds you: Management of human and animal bites. Injury 53(2): 227–236, 2022, https://doi.org/10.1016/j.injury.2021.11.045 ; Chodakewitz J, Bia FJ. Septic arthritis and osteomyelitis from a cat bite. Yale J Biol Med 61(6): 513–518, 1988]. We present a case report of a child with a pet cat bite to the right hand, leading to osteomyelitis of the trapezoid bone due to negligence.