Question 1

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

Accepted Answer

Collagen fibers in the dermis

Question 2

A patient presents with a flat, discolored area on their skin that does not alter the thickness or texture. Which type of lesion is this?

Accepted Answer

Macule

Question 3

Which of the following skin microbiota is most commonly found in moist areas such as the groin?

Accepted Answer

Malassezia species

Question 4

A vesicular rash is most characteristic of which viral infection?

Accepted Answer

Chickenpox

Question 5

Which of the following statements about the pathogenesis of chickenpox and shingles is correct?

Accepted Answer

Virions go latent in nerves during chickenpox infection and reactivate later in life as shingles.

Question 6

Which equation best represents the relationship between the number of cases of measles before and after the introduction of the MMR vaccine?

Accepted Answer

$$ C_{post} \u003c C_{pre} $$

Question 7

Which virulence factor is unique to Streptococcus pyogenes and not found in Staphylococcus aureus?

Accepted Answer

M-protein

Question 8

A patient develops a honey-colored crusted lesion on their face after scratching a vesicular rash. Which secondary lesion is most likely present?

Accepted Answer

Crust

Question 9

Which of the following is a plausible reason for the emergence of MRSA in hospitals?

Accepted Answer

Evolution of modified penicillin-binding proteins not affected by methicillin

Question 10

A burn patient develops a wound infection with a greenish-blue pigment and pus. Which organism is most likely responsible?

Accepted Answer

Pseudomonas aeruginosa

Question 11

Which of the following equations describes the risk of necrotizing fasciitis increasing with the number of virulence factors present?

Accepted Answer

$$ R = k 	imes V $$

Question 12

Which fungal organism is most commonly associated with athlete’s foot (tinea pedis)?

Accepted Answer

Trichophyton species

Question 13

A patient presents with a bright red macular rash in the groin area, accompanied by small white pustules. Which organism is most likely responsible?

Accepted Answer

Candida albicans

Question 14

Which of the following is the most effective prevention strategy for cutaneous leishmaniasis?

Accepted Answer

Avoiding sand fly bites using DEET-containing repellents

Question 15

Which equation best represents the relationship between the risk of conjunctivitis and improper contact lens hygiene?

Accepted Answer

$$ R_{conjunctivitis} \propto H_{improper} $$

Question 16

A patient presents with severe inflammation of the cornea, blurred vision, and sensitivity to light. Which condition is most likely present?

Accepted Answer

Keratitis

Question 17

Which organism is the leading cause of preventable microbial blindness worldwide?

Accepted Answer

Chlamydia trachomatis

Question 18

A patient develops a painless skin ulcer at the site of a sand fly bite that persists for months. Which disease is most likely present?

Accepted Answer

Cutaneous leishmaniasis

Question 19

Which of the following is a characteristic sign of measles (rubeola) infection?

Accepted Answer

Koplik’s spots in the mouth

Question 20

Which equation best represents the relationship between the risk of fungal keratitis and the presence of eye trauma or surgery?

Accepted Answer

$$ R_{keratitis} \propto T_{trauma} + S_{surgery} $$

Skin and Eye Infections: Structure, Defenses, and Microbial Diseases

Study Guide - Practice Questions