Swelling and Pain After a K-9 Encounter

When a patient gets bitten by a dog, there can be many issues doctors need to confront as treatment begins. Two doctors shared their experiences of a patient who was bitten by a dog and still had symptoms including swelling and pain 2 weeks after his K-9 encounter.

The study, published in the Cleveland Clinic Journal of Medicine reported that the patient was a 48-year-old man who was also diagnosed with gout, multiple sclerosis, and a history of methicillin-resistant Staphylococcus aureus (MRSA). He had been bitten on his arm from the wrist to the elbow and reported “feeling ‘feverish’ and having night sweats.”

Michael Lane, MD, and Thomas Taylor, MD, reported that while there had been initial improvement in the patient’s symptoms following the bite, swelling and pain began to develop. Other complications in diagnosis included his past anaphylactic reactions to both penicillin and cephalosporin. After being prescribed ciproflaxin and taking the medication for 5 days, there was no reported improvement in his condition.

The patient also described red streaks on his left forearm following a visit to the emergency room. The authors reported at the time of the patient’s examination, he had a “marked edema” on his left forearm and was complaining of joint pain in his left hand. With a fever of 100.2 degrees, doctors expressed concern about septic arthritis in the wrist, so the patient was admitted to the hospital.

Doctors considered the possibility of the patient having erysipeloid, which “often involves the underlying joint, is associated with edema, and produces systemic manifestations of fever and arthralgia.”

From radiography, doctors found “multiple foci of demineralization within the carpal bones and proximal radius, attributed to disuse,” the authors noted. The patient was also sent for magnetic resonance imaging, which showed “multiple bone infarcts in the carpal bones and the distal radius, with synovitis and fluid in the carpal joints and without adjacent osteomyelitis.”

Doctors also reported seeing “fluid in the soft tissues in the ulnar aspect of the left wrist as well as tenosynovitis involving the flexor carpi radialis tendon.” The patient had a current tetanus immunization and records for the dog also showed it was up to date with its rabies immunization.

When looking at the treatment for dog bites the authors said that amoxicillin taken orally and augmentin would be a “judicious choice,” for deep bites in the early stages of treatment. “However, our patient’s wound was no longer in the early stages of infection and he had a history of an adverse reaction to penicillin.”

The patient was treated with an intravenous of vancomycin, clindamycin and aztreonam “for coverage of dog-mouth flora,” the authors noted. Blood and synovial fluid culture tests also were negative and vancomycin was discontinued after 48 hours “when blood cultures did not grow staphylococcal organisms.” The treatment with clindamycin and aztreonam continued for 8 days “to treat possible infection with anaerobic and gram-negative enteric pathogens.”

Also as part of treatment, the patient was tested for autonomic dysfunction with a plastic pen case being drawn across each forearm. The authors reported the test revealed “a loss of tactile adherence,” particularly in areas where the patient was sweating, which interfered with the movement of the case. “The affected forearm was sensitive to light touch, with pain out of proportion to the stimulus,” they added.

Per the test results, the patient was diagnosed with complex regional pain syndrome type 1, which the authors noted was previously known as reflex sympathetic dystrophy. Symptoms, they said, can include pain, regional edema, joint stiffness and vasomotor disturbances among other issues.

“Complex regional pain syndrome is difficult to diagnose as it resembles many other ailments, such as gout, infection, bone tumor, stress fracture and arthritis,” the authors noted. “Its pathophysiology is poorly understood, but it is believed to result from a ‘short circuit,” in the reflex arc between somatic afferent sensory fibers and autonomic sympathetic efferent fibers, and this is thought to explain the increased sympathetic stimulation.”

Although the patient was originally diagnosed with septic arthritis, the authors said autonomic nerve testing can help doctors and healthcare professionals tell complex regional pain syndrome apart from other potential diagnoses. “However, autonomic testing is limited to academic centers and is not readily available.”

The authors studied a variety of treatment options including encouraging physical therapy at an early stage “to prevent contracture and enhance mobility.” While stellate ganglion nerve block has been used in some cases, its link to aggravating some symptoms of the syndrome has made it a “controversial treatment.”

Also to be avoided, they said, are treatments including immobilization and splinting that could result in adverse reactions for the patient and corticosteroids, “do not shorten the course or assuage symptoms and may increase edema.”

Other potentials include amitriptyline and pregabalin which have been used for courses of allodynia and hyperalgesia. The authors also noted that bisophoshonates “may decrease bone loss and pain and may be needed should the course of be complicated by myositis ossificans.”

The authors reported the patient had his left arm placed in a sling to help with the edema and pain and also began physical therapy when he was discharged and given a prescription of oxycodone as needed. Over the next 2 months, he showed signs of improvement in pain and swelling before falling and twisting his left wrist. That, they said, caused “intense pain and swelling of the forearm, hand and wrist.”

The patient was able to recover successfully from the injury, and with continued physical therapy the complex regional pain syndrome, “had completely resolved,” according to the authors.