Clinical Vignette XVIII

• Which of the following is this newborn male patient’s most likely diagnosis?

A two-day-old full-term male neonate born to apparently healthy parents – a G1P1 29-year-old female and a 31-year-old male – begins to exhibit unusual signs of poor feeding, increased vomiting, lethargy, and irritability. The male newborn had APGAR scores of 8 and 9, respectively, and seemed to be doing well clinically after a routine vaginal delivery without any noted peri-procedural complications. The standard newborn screening panel (the “heel stick” test) was performed approximately 24 hours after birth, and the infant’s filter paper card containing the samples of dried blood was sent to the appropriate lab to be tested for a wide assortment of serious medical conditions as part of a state-specific newborn screening panel. Depending on the hospital and the state lab performing the newborn screening tests, results from the newborn’s blood spot screening profile can take up to 5 to 7 days to complete and report. On physical examination, the newborn is afebrile, but before the clinician can proceed with the rest of the exam, she notices an unusually sweet-smelling odor emanating from the newborn male infant.

The clinician quickly tests the newborn’s urine using a standard urine ketone strip and a dinitrophenylhydrazine test. The standard urine ketone test strip is immediately positive for ketonuria. Knowing the urine dinitrophenylhydrazine test result can take up to ten minutes to yield a result, the clinician wastes no time and obtains some additional blood from the newborn male infant and has it sent to the hospital’s inpatient clinical laboratory service for an urgent quantitative plasma concentration amino acid analysis. Several minutes later, the urine dinitrophenylhydrazine test result demonstrates the evidence of a strong precipitate in opaque urine, indicating abnormally high urinary concentrations of α-ketoisocaproic acid, α-ketoisovaleric acid, and α-keto-β-methylvaleric acid. Based on the clinical picture, the limited lab testing results, and an intuitively high index of suspicion, the clinician quickly develops a working diagnosis and immediately begins preparing the appropriate medical treatment for the newborn male infant. Shortly thereafter, the test results of the newborn’s quantitative plasma concentration amino acid analysis revealed significantly elevated plasma concentrations of L-Leucine, L-Isoleucine, L-Valine, and L-allo-Isoleucine with decreased concentrations of other essential/non-essential amino acids such as L-Alanine, L-Glutamine, L-Glutamate, etc.

Which of the following is the most appropriate next step in the management of this patient?

A 38-year-old male is evaluated in the clinic for a dog bite on his right leg, which occurred earlier today at approximately 9 a.m. The patient reports being bitten by a random dog in his neighborhood while performing his morning 5-kilometer run. The patient states the dog was dark brown and probably medium-sized at about 60 lbs or so. In addition, the patient states he doesn’t recognize the dog since he started running the same 5-kilometer route two years ago, which involves a lot of running on side roads and into several different neighborhoods. The patient also reports that the attack was unprovoked. The patient states, “I was running on the side of the road as usual when I suddenly saw this dog run up to me, and I can recall thinking to myself that this dog wants to play.” Talk about being wrong! The dog bit me on my right thigh, which completely surprised me. Reflexively, I turned my back to it in an effort to run away, but the dog tried to bite me again. Luckily, I was wearing a weighted backpack, which got in the way. I immediately turned around to confront the dog and kicked it once, right on the side of its face, and it took off running. “I don’t know whose dog that is, nor does my neighbor, who saw the entire incident while tending to his garden.” The patient states, “After being bitten by that stray dog, I immediately went inside and cleaned the bite wound with soap and water for at least 20 minutes. Then I decided to visit the clinic to be safe.” This is the first time the patient has been bitten by any animal of significant size, which punctured the skin and drew some blood.

The patient is normally a healthy individual with no significant medical history. He takes no medications and has no known allergies. He does not drink alcohol, smoke cigarettes, chew tobacco, or use recreational drugs. He completed his Tdap vaccination series in 2007 and had a tetanus booster in 2017. He has been fully vaccinated against Hepatitis B, COVID-19, and all of the other pathogens required prior to attending public grade school in the United States. The remainder of his medical history, social history, and family history are non-contributory. On physical examination, vital signs are normal. There are two round puncture wounds noted on the mid-to-superior aspect of the vastus lateralis of the right thigh. Each puncture wound clearly breaks the skin surface to a depth of approximately 5 mm and measures approximately 7 mm in diameter. The outer distance between the puncture wounds measures approximately 55 mm, and the inner distance between the two puncture wounds measures approximately 39 mm. An area of edema and erythema surrounds each puncture wound. There is no gross evidence of nerve or tendon damage. There appears to be no gross involvement of bone tissue or adjacent joints. There are no visible foreign bodies in the wounds. There is no gross evidence of active bleeding at the time of the examination. There is mild tenderness to palpation of the wound site. The patient rates the pain as a 2/10 when the bite wound is palpated. The remainder of the physical examination is unremarkable. Cultures are obtained from the two puncture wounds. The puncture wounds are copiously irrigated with normal saline, dried, and dressed appropriately.

Which of the following is the most likely cause of this patient’s clinical signs and symptoms?

A 34-year-old male is evaluated in the medtigo Medical Center Emergency Department for new-onset chest palpitations and shortness of breath. The patient reports the chest palpitations started approximately eight hours ago at a friend’s Christmas party. The patient reports initially dismissing the chest palpitations until they worsened, and he also developed intermittent shortness of breath, prompting him to seek medical attention. He reports no associated chest pain and denies any prior history of experiencing similar symptoms. His medical history is notable for generalized anxiety disorder. He currently takes no medications. He consumes alcohol socially and on special occasions, has smoked about one pack of cigarettes per day since he was 24 years of age, and denies the use of recreational drugs.

He has no family history of early heart disease. The remainder of his medical history, family history, and social history is unremarkable. On physical examination, the patient smells of alcohol and marijuana. The temperature is 99.2°F (37.3°C), pulse rate is 112 beats/min and irregular; blood pressure is 138/85 mm Hg; respiration rate is 18/min, and oxygenation saturation is 97% while breathing ambient air. Height is 5’9” (175.25 cm), weight is 160 lbs (72.7 kg), and body mass index is 23.6 kg/m2. A cardiac exam reveals tachycardia with an irregular rate. The pulmonary exam is clear to auscultation bilaterally. The rest of the physical exam is unremarkable. Initial workup performed in the emergency department reveals the following:

CMP:  within reference range

TSH:  within reference range

CXR:  normal

ECG:  see below

Blood alcohol concentration:  0.164 mg/dL