What is the management of a dog bite with involvement of the Distal Interphalangeal (DIP) joint of the index finger and tendon involvement?

From the Guidelines

Management of a dog bite involving the distal interphalangeal (DIP) joint of the index finger with tendon involvement requires immediate surgical intervention and aggressive antibiotic therapy. The patient should be promptly referred to a hand surgeon for surgical debridement, irrigation, and exploration of the joint and tendon. The wound should not be primarily closed but left open to heal by secondary intention to prevent infection, as supported by the Infectious Diseases Society of America guidelines 1. Empiric antibiotic therapy should be started immediately with amoxicillin-clavulanate 875/125 mg orally twice daily for 7-14 days, as this has been shown to reduce the risk of infection in dog bite wounds, particularly in high-risk wounds such as those involving the hand 1. For patients with penicillin allergy, alternatives include doxycycline 100 mg twice daily or trimethoprim-sulfamethoxazole plus clindamycin. Tetanus prophylaxis should be administered if the patient's immunization status is not up to date. The affected hand should be immobilized in a functional position with a splint, and elevation is recommended to reduce swelling. Close follow-up within 24-48 hours is essential to reassess the wound and adjust treatment if necessary. Dog bites involving joints and tendons are high-risk injuries because the bacterial load from canine oral flora, particularly Pasteurella, Streptococcus, Staphylococcus, and anaerobes, can rapidly cause severe infection in these poorly vascularized structures, potentially leading to septic arthritis, osteomyelitis, or permanent functional impairment if not properly managed.

Some key points to consider in the management of this patient include:

• The importance of prompt surgical intervention to prevent infection and promote healing
• The use of empiric antibiotic therapy to reduce the risk of infection
• The need for tetanus prophylaxis to prevent tetanus infection
• The importance of immobilization and elevation of the affected hand to reduce swelling and promote healing
• The need for close follow-up to reassess the wound and adjust treatment if necessary, as recommended by the Infectious Diseases Society of America guidelines 1.

Overall, the management of a dog bite involving the DIP joint of the index finger with tendon involvement requires a comprehensive approach that includes prompt surgical intervention, aggressive antibiotic therapy, and close follow-up to prevent infection and promote healing.

From the Research

Management of Dog Bite with Involvement of the DIP Joint of the Index Finger and Tendon Involvement

• The management of a dog bite with involvement of the Distal Interphalangeal (DIP) joint of the index finger and tendon involvement requires careful consideration of the risk of infection and the need for antibiotic prophylaxis 2, 3.
• The wound should be cleaned and copiously irrigated with normal saline, and explored for tendon or bone involvement and possible foreign bodies 2.
• Antibiotic prophylaxis should be considered, especially if there is a high risk of infection, such as with puncture wounds, wounds to the hand, and in persons who are immunosuppressed 2, 3.
• Amoxicillin/clavulanate is the first-line prophylactic antibiotic for dog bites 2, 3.
• The need for rabies prophylaxis should also be addressed, as even domestic animals are often unvaccinated 2, 4.
• In cases where the dog bite results in osteomyelitis, such as Candida parapsilosis osteomyelitis, treatment with fluconazole may be effective 5.
• It is also important to consider the patient's tetanus status and provide appropriate tetanus prophylaxis if necessary 4.

Tendon Involvement and DIP Joint Involvement

• Tendon involvement in dog bites requires careful management to prevent infection and promote healing 2, 3.
• Involvement of the DIP joint of the index finger can lead to complications such as osteomyelitis, and requires prompt treatment with antibiotics and possibly surgery 5.
• The use of amoxicillin-clavulanic acid with or without enrofloxacin has been shown to be effective in the treatment of moderate grade dog bite wounds, including those with tendon involvement 6.