Question 1

Which of the following is NOT a defense mechanism of the skin against microbial infection?

Accepted Answer

Production of hemoglobin in the epidermis

Question 2

A patient presents with a honey-colored crusted lesion on the face. Which organism is most likely responsible for this presentation?

Accepted Answer

Staphylococcus aureus

Question 3

Which of the following best explains why diabetics are at increased risk for cutaneous candidiasis?

Accepted Answer

High blood sugar levels lead to vascular damage, impairing skin defenses

Question 4

A 7-year-old child develops a fever and an itchy vesicular rash that starts on the face and spreads to the trunk. Which virus is the most likely cause?

Accepted Answer

Varicella-zoster virus

Question 5

Which of the following statements about Staphylococcal scalded skin syndrome is TRUE?

Accepted Answer

It is caused by exfoliative toxins produced by Staphylococcus aureus

Question 6

A burn patient develops a blue-green pus at the wound site. Which bacterial pigment is responsible for this coloration, and what is its effect?

Accepted Answer

Pyocyanin; generates reactive oxygen species that damage tissue

Question 7

Which of the following is a distinguishing feature of smallpox compared to chickenpox?

Accepted Answer

Smallpox lesions are more likely to be found on the face and extremities, while chickenpox lesions are more concentrated on the trunk

Question 8

A wrestler develops vesicular lesions on the forearm after a match. Which condition is most likely, and what is the causative agent?

Accepted Answer

Herpes gladiatorum; Herpes simplex virus

Question 9

Which of the following best describes the mechanism by which lysozyme protects the skin?

Accepted Answer

It breaks down peptidoglycan in bacterial cell walls

Question 10

A patient presents with a painless, blackened ulcer on the arm after handling animal hides. Which organism is most likely responsible?

Accepted Answer

Bacillus anthracis

Question 11

Which of the following is a common complication of measles (rubeola) infection?

Accepted Answer

Encephalitis leading to possible permanent brain damage

Question 12

A 3-year-old child in daycare develops blister-like sores in the mouth and lesions on the hands and feet. Which virus is the most likely cause?

Accepted Answer

Coxsackievirus A16

Question 13

Which of the following is the most effective way to prevent cutaneous leishmaniasis in endemic areas?

Accepted Answer

Avoiding sand fly bites by using DEET-containing repellents and covering exposed skin

Question 14

A patient with a history of acne is prescribed a retinoid drug. What is the primary mechanism by which this drug helps treat acne?

Accepted Answer

Decreases sebum production

Question 15

Which of the following is a characteristic of dermatophyte infections (ringworm)?

Accepted Answer

They cause scaly, blistered, or discolored skin and can infect hair and nails

Question 16

A patient presents with rapidly spreading red, swollen, and painful skin on the leg, accompanied by fever and leukocytosis. Which diagnosis is most likely?

Accepted Answer

Cellulitis

Question 17

Which of the following best explains why Pseudomonas aeruginosa is a common cause of healthcare-acquired infections?

Accepted Answer

It forms biofilms on indwelling devices and is resistant to many antibiotics

Question 18

A newborn develops a bright red macular rash with small white pustules in the diaper area. Which organism is most likely responsible?

Accepted Answer

Candida albicans

Question 19

Which of the following is a key difference between primary and secondary skin lesions?

Accepted Answer

Primary lesions are directly associated with a specific disease process, while secondary lesions may develop from primary lesions

Question 20

A patient with a deep wound develops foul-smelling gas and tissue necrosis. Which organism is most likely responsible, and what is the likely diagnosis?

Accepted Answer

Clostridium perfringens; gas gangrene

Microbiology Study Guide: Skin Infections

Study Guide - Practice Questions

Study Guide - Flashcards