Signs of contagion after animal bites develop within hours to several days after injury. infection is the common reason that patients seek medical attention more than 12 hours after injury, whereas those seen earlier are more concerned with prophylaxis or surgical repair. Findings indicative of wind infection include localized swell, erythema, and pain with or without serosanguineous or purulent drain ( Fig. 260-1 ). The clinical findings vary with the infecting organism, locate of injury, and type of bite. The characteristic findings of P. multocida infection, which include acute pain, swelling, and erythema, develop quickly, often within hours after wound. Cellulitis is normally apparent within 24 to 36 hours after the pungency ; occasionally the manifestation is delayed for 3 to 5 days. Despite these acute local symptoms, patients broadly are afebrile, and less than 20 percentage have lymphangitis and regional adenitis. Patients with wound infection caused by staphylococcus or streptococci normally experience less acute pain, have a check between injury and the onset of symptoms of days quite than hours, and may have a more circulate, less ardent cellulitis. Gas in tissues of the forearm clinically suggestive of clostridial accelerator necrosis has occurred in infections caused by Streptococcus anginosus and Streptococcus mutans after horse morsel lacerations.68 Wound infection clinically resembling that caused by P. multocida from which the relate but more unusual gram-negative rod Actinobacillus lignieresii was isolated has been reported in a child who sustained a facial bite by a horse.26 “ Seal finger ” deserves mention because failure to initiate appropriate therapy can result in permanent sequela. The etiological agent is unknown ; a potential function is suggested for Mycoplasma.9 Infection can result from contact through a laceration from the skin of a seal or from a cachet tooth- or claw-associated puncture wound.67 The incubation period averages 4 to 8 days, and the onset is characterized by dangerous pain and frequently massive intumescence and erythema. In some cases, regional adenopathy and ascending lymphangitis occur. A predilection for affair of the joint close to the inoculation site has been noted. Once the diagnosis is established, treatment should be initiated with a tetracycline, the drug class of option. In patients with systemic infections transmitted by animal bites, the incubation periods and clinical manifestations vary with the causative agent. For example, streptobacillary rat-bite fever occurs after an incubation period of less than 1 workweek, whereas spirillary rat-bite fever, or sodoku, has a 2-week asymptomatic interval after the sting. however, rat-bite fevers caused by Spirillum minor and Streptobacillus moniliformis can occur together. For most of the infections listed in postpone 260-2, the pungency wind serves as the site of inoculation and has healed wholly during the incubation time period. For example, fatal encephalitis has resulted from the bite or scratch of a tamper that is actively shedding B virus ( Herpesvirus simiae ). institution of acyclovir treatment intravenously at the prison term of wound may abort progress of the disease.11,73 The symptoms heralding the attack of systemic infections caused by animal bites do not depend on the mood of transmission and are discussed in their respective chapters. A high index of misgiving can be required to trace the infection to the animal source. For exercise, most cases of human harass in the United States leave from bites by infect fleas, but reach with a domestic cat-o’-nine-tails infected with Yersinia plague can be the source of infection.38 With tularemia, an ulcerative81 or pustular34 lesion develops at the bite site 4 to 7 days after injury and is associated with fever, chills, and painful regional adenopathy. In a character of Mycobacterium marinum infection that developed after a dolphin bite, one of several discrete fluctuant masses containing the isolate developed in an area just proximal to the original wound.37 With cat-scratch disease caused by Bartonella henselae, a papule or pustule may be introduce at the original pungency locate when systemic signs develop.
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The call on the carpet and tooth of dogs are probable to produce multiple puncture wounds, a well as jagged lacerations with devitalize tissue. These lesions can be associated with gloomy skull fractures, sometimes in more than one cranial region.100 Puncture wounds, peculiarly those inflicted by cat bites, much are deceptively innocuous. inoculation of organism deep into ill vascularized areas, such as tendon sheaths, fascia, joints, and bones, is probable to result in an septic wound.
Some of the complications resulting from steer extension or generalized scatter of infection caused by animal bites are summarized in postpone 260-3. tenosynovitis caused by P. multocida can be apparent within hours or can present days to weeks after wound, when doggedness of swelling, affection or pain, and a mass overlying the involve tendon sheath suggest the diagnosis. Pasteurella osteomyelitis that develops after a cat bite is characterized by pain, swelling, and tenderness over the involve bone.55 With chronic infection, a draining sinus or a persistently draining injure can be the salute signs. When the periosteum has been entered, osteomyelitis can develop despite early administration of local and antibiotic treatment. feline incisors are more likely to penetrate the periosteum than are canine incisors, but osteomyelitis can occur as a consequence of cad bites as well.55 Bites to the cranium happen with relative frequency in little children because their heads are at the grade of the mouth of medium- to large-sized dogs. Complications of perforating cranial bites in children include compound depressed skull fractures, dural lacerations, and extensive intracerebral injuries, which can prove fatal.17,100 Brain abscess and meningitis can occur as complications of these injuries ( see Table 260-3 ). Generalized or systemic complications from animal bites occur normally, but not entirely, in hosts with alter immune status. Bacteremia and fatal endocarditis caused by this organism have occurred in immunocompetent patients. Common underlying findings in infections associated with Capnocytophaga canimorsus are splenectomy, dipsomania, and chronic lung disease.79 Disseminated intravascular curdling, hypotension, cutaneous gangrene, and nephritic failure have occurred in patients with leukemia or lymphoma and in association with steroid hormone therapy. Symptoms ensue 1 day to 2 weeks after andiron or, occasionally, big cat bites occur ; the overall mortality rate from C. canimorsus blood poisoning exceeds 20 percent.25 Although removal of bilaterally affected knee joint prostheses was required to achieve cure of infection caused by P. multocida and Pseudomonas aeruginosa in one report,72 cure besides has been achieved with antibiotics and drain with the prosthesis remaining in situ .