A 3-year-old, previously healthy girl is brought to the emergency department due to difficulty swallowing. The patient has had fever, chills, malaise, myalgias, and sore throat for a week. Today, she is refusing to drink fluids and spits out any liquids given to her. The patient has a history of small puncture wounds on her left forearm that the family noticed 2 months prior. It is unclear how the wounds occurred, but the site was cleaned and dressed and has since healed completely. Temperature is 40 C (104 F), blood pressure is 90/60 mm Hg, pulse is 144/min, and respirations are 34/min. Examination shows an agitated, disoriented girl with copious drool and facial grimacing who frequently spits saliva. There is numbness surrounding a small, healed scar on the left forearm. The neck is supple with full range of motion. Which of the following is the most likely diagnosis?

Question

A 3-year-old, previously healthy girl is brought to the emergency department due to difficulty swallowing.  The patient has had fever, chills, malaise, myalgias, and sore throat for a week.  Today, she is refusing to drink fluids and spits out any liquids given to her.  The patient has a history of small puncture wounds on her left forearm that the family noticed 2 months prior.  It is unclear how the wounds occurred, but the site was cleaned and dressed and has since healed completely.  Temperature is 40 C (104 F), blood pressure is 90/60 mm Hg, pulse is 144/min, and respirations are 34/min.  Examination shows an agitated, disoriented girl with copious drool and facial grimacing who frequently spits saliva.  There is numbness surrounding a small, healed scar on the left forearm.  The neck is supple with full range of motion.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d58e_9226_bc81_e71204c8d66a_MD0003_00 Rabies is a fatal, neurotropic viral disease transmitted via exposure to saliva from an infected animal through a bite. In the United States, bats and racoons account for most human exposures. Because bat teeth are small and needle shaped, many bites may go unnoticed, particularly if the patient is asleep, which likely occurred in this case. The virus amplifies in muscle cells at the inoculation site and travels centrally within the nerves to reach the spinal cord, a process that can take several weeks. Therefore, initial symptoms typically develop 1-3 months after exposure and are characterized by a nonspecific prodrome (eg, fever, chills, sore throat, malaise) lasting a few days; pain, tingling, and/or numbness of the bite wound, as seen in this patient, is highly suggestive of clinical rabies. From the spinal cord, the virus spreads quickly to the brain then disseminates peripherally, particularly affecting muscles and other highly innervated areas (eg, salivary glands). Therefore, most patients develop encephalitic symptoms, including the pathognomonic hydrophobia (ie, fear of liquids, refusal to drink) and aerophobia (ie, fear of drafts of air) due to pharyngeal spasms. Dysautonomia (eg, hypersalivation), muscle contractions (eg, grimacing, opisthotonos), and fluctuating agitation are also common. Almost all patients develop coma and die within weeks. opisthotonos (Choices A and D) Herpes simplex virus encephalitis is spread via close contact with an infected person's secretions and presents with fever, headache, seizure, and focal neurologic deficits. West Nile virus (transmitted via mosquito bites) can present with nonspecific symptoms (eg, fever, myalgia) and meningitis/encephalitis. Neither condition would explain this patient's hydrophobia, excessive drooling, facial grimacing, and wound paresthesia. (Choice C) Tetanus can be contracted through a bite but presents with trismus, which is not seen in this patient, who is able to open her mouth. In addition, unlike rabies, tetanus symptoms develop within 3 weeks of exposure; this patient sustained wounds 2 months prior. (Choice E) Clostridium botulinum infection of a puncture wound can lead to wound botulism and classically causes symmetric descending weakness, which is not seen here. In addition, wound botulism develops 1-2 weeks after exposure, whereas this patient's wound from 2 months prior is well healed. Educational objective: Rabies is a fatal, neurotropic viral disease transmitted to humans by exposure to saliva from an infected animal through a bite. Paresthesia of the bite wound is characteristic, and after an incubation period of 1-3 months, patients develop encephalopathy, dysautonomia, and hydrophobia, followed by coma and death. References: Rabies surveillance in the United States during 2016. (http://www.ncbi.nlm.nih.gov/pubmed/29595389) Human rabies-Wyoming and Utah, 2015. (http://www.ncbi.nlm.nih.gov/pubmed/27253630)

A 3-Year-Old, Previously Healthy Girl Is Brought to the Emergency