Pediatric Infectious Diseases

1. A 9-month-old child presents to the emergency room with inconsolable crying and fever. His mother reports that he was in his usual state of health until yesterday evening. At that time, he developed cough and runny nose. He was also febrile to 101 F per his mother. Since that time he has continued to have fever, despite treatment with children s ibuprofen. Over the course of the day the child has been inconsolably crying, grabbing his head, and complaining of pain. Past medical history is unremarkable. The birth history is normal, and developmental milestones have been appropriate. The patient has no allergies, takes no medications and has never been hospitalized. On your examination, temperature is 103 F, heart rate is 156, blood pressure is 95/47, and respirations are 28. The child appears irritable and uncomfortable. Lung and cardiovascular exam are normal. There are no rashes. You note a bulging anterior fontanel. When you flex the child s neck, he whimpers and flexes his hips and knees. You perform a lumbar puncture which reveals glucose 23 mg/dl, protein 150 mg/dl, and 300 WBC/microliter (90 % PMN s). After obtaining appropriate cultures, what is the MOST APPROPRIATE empiric parenteral antibiotic regimen?

Piperacillin/tazobactam (Zosyn) monotherapy

Vancomycin and ceftriaxone

Vancomycin and acyclovir

Vancomycin and ampicillin

Vancomycin and rifampin

The most appropriate empiric parenteral antibiotic regimen for this 9-month-old child is vancomycin and ceftriaxone. This is because the child presents with symptoms consistent with meningitis, including fever, irritability, and a bulging anterior fontanel. The lumbar puncture results also support the diagnosis of meningitis, with low glucose, high protein, and elevated white blood cell count. Vancomycin and ceftriaxone provide broad coverage against the most common pathogens causing meningitis in this age group, including Streptococcus pneumoniae and Neisseria meningitidis.

Explanation

The most appropriate empiric parenteral antibiotic regimen for this 9-month-old child is vancomycin and ceftriaxone. This is because the child presents with symptoms consistent with meningitis, including fever, irritability, and a bulging anterior fontanel. The lumbar puncture results also support the diagnosis of meningitis, with low glucose, high protein, and elevated white blood cell count. Vancomycin and ceftriaxone provide broad coverage against the most common pathogens causing meningitis in this age group, including Streptococcus pneumoniae and Neisseria meningitidis.

2. A 14-year-old girl presents to the emergency department with her mother. She has a one-week history of pain in her left knee. She has had a low grade fever and notes that she had a round ring-like rash five months ago. She lives in the northeastern United States and frequently hikes in the woods. Recently her eightyear- old brother had an erythematous rash that was on his face and arms. His rash got worse if he took a warm bath or was out in the sun. He has been afebrile. Physical examination is essentially normal except for the patient s left knee which is moderately tender with an effusion. There are no effusions of any other joints. She has no conjunctivitis or scleral changes on examination. There are no skin lesions or rashes. WHICH of the following is the best initial treatment plan for this patient?

Cefixime

Ceftriaxone

Ciprofloxacin

Doxycycline

Trimethoprim-Sulfamethoxazole

The patient's history and symptoms suggest that she may have Lyme disease, which is commonly transmitted through tick bites in the northeastern United States. The round ring-like rash she had five months ago is consistent with erythema migrans, a characteristic rash seen in Lyme disease. Additionally, her brother's rash and the aggravation of symptoms with warm baths or sun exposure are also suggestive of Lyme disease. Doxycycline is the treatment of choice for Lyme disease in patients of all ages, including children and adolescents. Therefore, the best initial treatment plan for this patient would be to prescribe Doxycycline.

Explanation

The patient's history and symptoms suggest that she may have Lyme disease, which is commonly transmitted through tick bites in the northeastern United States. The round ring-like rash she had five months ago is consistent with erythema migrans, a characteristic rash seen in Lyme disease. Additionally, her brother's rash and the aggravation of symptoms with warm baths or sun exposure are also suggestive of Lyme disease. Doxycycline is the treatment of choice for Lyme disease in patients of all ages, including children and adolescents. Therefore, the best initial treatment plan for this patient would be to prescribe Doxycycline.

3. A 7-year-old boy presents to the emergency room with fever, headache, and rash. He recently returned from a hunting trip to North Carolina with his father. His father states he and his son had several tick bites. There are no meningeal signs on examination. Labs are significant for thrombocytopenia and hyponatremia. WHICH of the following best describes the typical rash associated with most likely cause of illness in this patient?

A diffuse maculopapular rash which appears symmetrically over the body

A diffuse pruritic vesicular rash which appears in pinpoint lesions over the body

A macular rash which begins on the head and spreads to the remainder of the body in adescending fashion

A petechial rash which first appears on the extremities and moves onto the trunk in acentripetal fasion

Erythema of the cheeks, followed by a lacy-reticulated rash over the trunk, especially theextremities

The presence of thrombocytopenia and hyponatremia in this patient suggests a possible diagnosis of Rocky Mountain spotted fever (RMSF), which is caused by the bacterium Rickettsia rickettsii. RMSF is commonly transmitted through tick bites, and the typical rash associated with this illness is a petechial rash. Petechiae are small, pinpoint-sized hemorrhages that appear as small red or purple spots on the skin. In RMSF, the rash typically starts on the extremities (such as the wrists and ankles) and then spreads centrally to involve the trunk. This pattern of rash distribution is described as centripetal.

Explanation

The presence of thrombocytopenia and hyponatremia in this patient suggests a possible diagnosis of Rocky Mountain spotted fever (RMSF), which is caused by the bacterium Rickettsia rickettsii. RMSF is commonly transmitted through tick bites, and the typical rash associated with this illness is a petechial rash. Petechiae are small, pinpoint-sized hemorrhages that appear as small red or purple spots on the skin. In RMSF, the rash typically starts on the extremities (such as the wrists and ankles) and then spreads centrally to involve the trunk. This pattern of rash distribution is described as centripetal.

4. An 8-year-old girl is brought to the hospital for evaluation by her worried parents. It is summertime and their daughter has been playing outside much of the summer. She has had frequent mosquito bites. She has had no other animal bites or contact that she or her parents remember. She has previously been in good health. When she woke up this morning, she had complained to her mother of a headache which has become significantly worse throughout the day. Her mother reports low-grade fever as well. She has vomited once today and feels nauseous again while waiting to be evaluated. She denies photophobia or other symptoms. Several of her friends have had similar symptoms over the past several days. Physical examination shows an uncomfortable but non-toxic appearing child who is holding her head, but is able to converse with you. She is alert and oriented appropriately and although she is uncomfortable, she is not irritable. Vital signs are as follows: T 38.0 C, pulse 88, BP 98/52, RR 20. She has mild nuchal rigidity but otherwise has normal physical examination, including normal neurologic findings. You decide to perform a lumbar puncture with the following CSF findings: CSF leukocytes 110 cells with 92% lymphocytes CSF protein 80 mg/dl CSF glucose 90 mg /dl The child is admitted for observation and recovers without incident. What is the MOST LIKELY etiology of her infection?

A gram positive bacteria

An arbovirus

Parvovirus B-19 infection

Herpes Simplex virus

An enterovirus

The most likely etiology of the girl's infection is an enterovirus. This is suggested by the clinical presentation of headache, fever, nausea, vomiting, and mild nuchal rigidity, which are consistent with viral meningitis. The CSF findings of elevated lymphocytes and normal glucose and protein levels further support this diagnosis. Enteroviruses are a common cause of viral meningitis, especially during the summer months, and the fact that several of her friends have had similar symptoms over the past several days also suggests a viral etiology. Gram positive bacteria, arboviruses, Parvovirus B-19, and Herpes Simplex virus are less likely based on the clinical presentation and CSF findings.

Explanation

The most likely etiology of the girl's infection is an enterovirus. This is suggested by the clinical presentation of headache, fever, nausea, vomiting, and mild nuchal rigidity, which are consistent with viral meningitis. The CSF findings of elevated lymphocytes and normal glucose and protein levels further support this diagnosis. Enteroviruses are a common cause of viral meningitis, especially during the summer months, and the fact that several of her friends have had similar symptoms over the past several days also suggests a viral etiology. Gram positive bacteria, arboviruses, Parvovirus B-19, and Herpes Simplex virus are less likely based on the clinical presentation and CSF findings.

5. You are evaluating a 4 year-old-boy in the emergency department for bloody diarrhea. He has been ill for about two days with fever and diarrhea. He has previously been well and has no underlying chronic health conditions. Evaluation shows a child who, although he indeed has frequent loose stools, some with spots of blood in them, is adequately hydrated and is not compromised either hemodynamically or neurologically. In the above scenario, infection with WHICH of the following agents would NOT require treatment with antibiotic therapy?

Salmonella species

Amoebic dysentery

Campylobacter

Clostridium dificile

Yersinia

In the given scenario, infection with Salmonella species would not require treatment with antibiotic therapy. This is because Salmonella infections in otherwise healthy individuals, like the 4-year-old boy in this case, are usually self-limiting and resolve on their own without the need for antibiotics. The boy's adequate hydration and lack of hemodynamic or neurological compromise suggest that his body is effectively fighting off the infection. Antibiotic therapy is typically reserved for severe cases or for individuals with underlying health conditions that put them at higher risk for complications.

Explanation

In the given scenario, infection with Salmonella species would not require treatment with antibiotic therapy. This is because Salmonella infections in otherwise healthy individuals, like the 4-year-old boy in this case, are usually self-limiting and resolve on their own without the need for antibiotics. The boy's adequate hydration and lack of hemodynamic or neurological compromise suggest that his body is effectively fighting off the infection. Antibiotic therapy is typically reserved for severe cases or for individuals with underlying health conditions that put them at higher risk for complications.

6. A 17-year-old female comes to the emergency department for evaluation of persistent vaginal discharge. She does not want to go to her pediatrician s office for this particular concern. She has had several episodes in the past two years which have been self-diagnosed as yeast infections. They have always responded to over-the-counter medications such as clotrimazole. She admits to being sexually active with a history of multiple male partners in the past. She reports all previous partners as being healthy. She admits to vaginal discharge for the past several weeks. She recently completed another over-the-counter remedy for this problem, but had no improvement in the discharge this time. She denies a history of sexually transmitted disease. She denies any vaginal lesions or vesicles. She is currently using oral contraceptives for birth control; she does not regularly use any type of barrier protection. Pelvic examination is notable for a small amount of discharge from the cervical os. There is no adnexal or cervical motion tendeness. For the patient described above, WHICH of the following is the most appropriate empiric pharmacologic therapy after obtaining specimens for culture?

Azithromycin by mouth and ceftriaxone intramuscularly

Azithromycin by mouth, ceftriaxone intramuscularly and penicillin-G intramuscularly

Ceftriaxone intramuscularly

Ceftriaxone and penicillin-G intramuscularly

Penicillin-G intramuscularly

The patient's history of multiple sexual partners, persistent vaginal discharge, and lack of improvement with over-the-counter remedies suggest a sexually transmitted infection (STI). The most appropriate empiric pharmacologic therapy for suspected STIs is a combination of azithromycin and ceftriaxone. Azithromycin is effective against Chlamydia trachomatis, which is a common cause of STIs, and ceftriaxone is effective against Neisseria gonorrhoeae, another common cause. This combination covers the two most likely pathogens and is the recommended treatment in this scenario. Penicillin-G is not indicated as the patient denies a history of syphilis, and there are no findings suggestive of syphilis on examination.

Explanation

The patient's history of multiple sexual partners, persistent vaginal discharge, and lack of improvement with over-the-counter remedies suggest a sexually transmitted infection (STI). The most appropriate empiric pharmacologic therapy for suspected STIs is a combination of azithromycin and ceftriaxone. Azithromycin is effective against Chlamydia trachomatis, which is a common cause of STIs, and ceftriaxone is effective against Neisseria gonorrhoeae, another common cause. This combination covers the two most likely pathogens and is the recommended treatment in this scenario. Penicillin-G is not indicated as the patient denies a history of syphilis, and there are no findings suggestive of syphilis on examination.

7. A 7-year-old boy is seen in the emergency department after receiving a bite wound to his leg from a neighbor s dog. The bite was a provoked attack as the boy was teasing the dog with a water hose. The dog is up to date on its rabies vaccinations. The boy received a tetanus booster at 5 years of age. WHICH of the following is the MOST APPROPRIATE course of action for this patient?

Clean the wound and start amoxicillin

Clean the wound and start amoxicillin-clavulanate (Augmentin)

Clean the wound and start ciprofloxacin (Cipro)

Clean the wound and start cephalexin (Keflex)

Clean the wound only and watch for infection before starting antibiotic therapy

The most appropriate course of action for this patient is to clean the wound and start amoxicillin-clavulanate (Augmentin). This is because the patient has a bite wound, which carries a high risk of infection due to the presence of bacteria in the dog's mouth. Amoxicillin-clavulanate is a broad-spectrum antibiotic that covers the most common bacteria found in dog bites, including both aerobic and anaerobic organisms. Cleaning the wound alone may not be sufficient to prevent infection, and starting antibiotic therapy is recommended in this case.

Explanation

The most appropriate course of action for this patient is to clean the wound and start amoxicillin-clavulanate (Augmentin). This is because the patient has a bite wound, which carries a high risk of infection due to the presence of bacteria in the dog's mouth. Amoxicillin-clavulanate is a broad-spectrum antibiotic that covers the most common bacteria found in dog bites, including both aerobic and anaerobic organisms. Cleaning the wound alone may not be sufficient to prevent infection, and starting antibiotic therapy is recommended in this case.

8. An 18-year-old female is admitted to your hospital service for inpatient management of severe migraine headache. Her headache is treated and she improves. She mentions to you that she will be traveling to rural areas of Haiti following high school graduation for a summer exchange program. She expects to be spending many hours daily out in the sun. She wants to know what medications or immunizations she will need to take in order to protect herself from malaria. WHICH of the following would NOT be an appropriate choice for malaria prophylaxis in this patient?

Atovaquone and proguanil (Malarone)

Chloroquine

Sulfadoxine and pyramethamine (Fansidar

Mefloquine

Praziquantel

Praziquantel is not an appropriate choice for malaria prophylaxis in this patient. Praziquantel is actually used to treat parasitic infections such as schistosomiasis, not malaria. The other options listed (Atovaquone and proguanil, Chloroquine, sulfadoxine and pyramethamine, and Mefloquine) are all commonly used for malaria prophylaxis.

Explanation

Praziquantel is not an appropriate choice for malaria prophylaxis in this patient. Praziquantel is actually used to treat parasitic infections such as schistosomiasis, not malaria. The other options listed (Atovaquone and proguanil, Chloroquine, sulfadoxine and pyramethamine, and Mefloquine) are all commonly used for malaria prophylaxis.