CompTIA
Checkpoint
ISC
HP
Dell
EC-Council
EXIN
Fortinet
ITIL®
Juniper
PMI
Microsoft
VMware
Avaya
Google
Salesforce
Amazon
Palo Alto Networks
Certiport
ISC2
All Vendors
  2. Home
  3. Exams
  4. USMLE
  5. STEP3

Free STEP3 Exam Braindumps (page: 92)

Page 91 of 202
PDF with 804 Questions

You are working in the emergency department and are called to perform a lumbar puncture on a 3-month- old infant who presented with fever and lethargy. The spinal fluid that you obtain is turbid. The laboratory reports that there are 200 WBCs and 5 RBCs per high-power field (HPF). Ninety-five percent of the WBCs in the spinal fluid are neutrophils

If the laboratory result showed that 98% of the WBCs in the spinal fluid were lymphocytes, what would be the most likely etiology of the infection?

  1. Mycobacterium tuberculosis
  2. HSV
  3. trachomatis
  4. RSV
  5. nonpolio enteroviruses

Answer(s): E

Explanation:

In children over 1 month of age, the most common causes of bacterial meningitis are S. pneumoniae and Neisseria meningitidis. HIB was also a frequent cause of this disease prior to the widespread use of the HIB vaccine. GBS, E. coli, and HSV would be more common causes of CNS infections in neonates. (McMillin et al., 1999, Chap. 142) Nonpolio enteroviruses are the most common causes of aseptic meningitis in childhood. There are approximately 65 nonpolio enteroviruses, including the Coxsackieviruses, echoviruses, and enteroviruses. Children are the main susceptible population and transmission is from child to child, via fecal-oral or oraloral (respiratory) contact. Meningitis may result from viremic spread of the virus. Treatment of this is supportive.



You are working in a community clinic on a Native American reservation. A mother brings in her 8- year-old son for an ophthalmic evaluation. On examination, you find bilateral corneal ulceration and decreased visual acuity. What is the most common infectious cause of blindness in the world?

  1. HSV
  2. C. trachomatis
  3. GAS
  4. S. pneumoniae
  5. coli

Answer(s): B

Explanation:

The most common infectious cause of blindness in the world is trachoma. Trachoma is the chronic effect of a C. trachomatis infection acquired in the perinatal period. The most common cause of blindness in the world is noninfectious



A 4-year-old girl is brought in to the office by her mother. She developed chicken pox about 6 days ago. She appeared to be recovering well but mother became concerned because she was persistently scratching at several of the lesions and they were not healing. On examination, the child is afebrile and generally well appearing. On examination of her skin you see the following image



What is the most likely current diagnosis?

  1. tinea corporis
  2. impetigo
  3. warts
  4. contact dermatitis
  5. reactivated chicken pox

Answer(s): B

Explanation:

The image provided shows a classic case of impetigo. This is a common skin infection of childhood. It frequently occurs following a case of chickenpox and is due to the child picking or scratching at the varicella lesions, resulting in a secondary bacterial infection. GAS infection is the most common cause of impetigo associated with varicella infections. It is markedly more prevalent than the next most common infectious agent, S. aureus. Tinea corporis, often due to T. rubrum, is also known as ringworm. It classically is a circular lesion with a red, raised border, and central clearing. Contact dermatitis, from exposure to an irritant such as poison ivy, often causes plaques of erythema and edema with superimposed vesicles. This is also frequently secondarily infected with GAS from scratching. Warts, caused by the human papilloma virus, do not typically appear as the lesions in the image. Of the options listed, oral cephalexin would be the most appropriate initial therapy. Most GAS isolates are sensitive to first-generation cephalosporins, such as cephalexin. Topical steroids are useful for inflammatory or allergic conditions, topical nystatin for a fungal infection (such as tinea corporis) and oral acyclovir can be used early in the course of a varicella infection.



A 4-year-old girl is brought in to the office by her mother. She developed chicken pox about 6 days ago. She appeared to be recovering well but mother became concerned because she was persistently scratching at several of the lesions and they were not healing. On examination, the child is afebrile and generally well appearing. On examination of her skin you see the following image



What is the most likely responsible agent?

  1. Trichophyton rubrum
  2. poison ivy
  3. human papilloma virus
  4. GAS
  5. varicella-zoster virus

Answer(s): D

Explanation:

The image provided shows a classic case of impetigo. This is a common skin infection of childhood. It frequently occurs following a case of chickenpox and is due to the child picking or scratching at the varicella lesions, resulting in a secondary bacterial infection. GAS infection is the most common cause of impetigo associated with varicella infections. It is markedly more prevalent than the next most common infectious agent, S. aureus. Tinea corporis, often due to T. rubrum, is also known as ringworm. It classically is a circular lesion with a red, raised border, and central clearing. Contact dermatitis, from exposure to an irritant such as poison ivy, often causes plaques of erythema and edema with superimposed vesicles. This is also frequently secondarily infected with GAS from scratching. Warts, caused by the human papilloma virus, do not typically appear as the lesions in the image. Of the options listed, oral cephalexin would be the most appropriate initial therapy. Most GAS isolates are sensitive to first-generation cephalosporins, such as cephalexin. Topical steroids are useful for inflammatory or allergic conditions, topical nystatin for a fungal infection (such as tinea corporis) and oral acyclovir can be used early in the course of a varicella infection






Post your Comments and Discuss USMLE STEP3 exam with other Community members:

STEP3 Exam Discussions & Posts