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21.E: Skin and Eye Infections (Exercises)

21.1: Anatomy and Normal Microbiota of the Skin and Eyes

Multiple Choice

_______
______ glands produce a lipid-rich substance that contains proteins and minerals and protects the skin.

A. Sweat
B. Mammary
C. Sebaceous
D. Endocrine

C

Which layer of skin contains living cells, is vascularized, and lies directly above the hypodermis?

A. the stratum corneum
B. the dermis
C. the epidermis
D. the conjunctiva

B

Fill in the Blank

The ________ is the outermost layer of the epidermis.

stratum corneum

The mucous membrane that covers the surface of the eyeball and inner eyelid is called the ________.

conjunctiva

Short Answer

What is the role of keratin in the skin?

What are two ways in which tears help to prevent microbial colonization?

Which label indicates a sweat gland?

(credit: modification of work by National Cancer Institute)

Critical Thinking

Explain why it is important to understand the normal microbiota of the skin.

Besides the presence or absence of ulceration, how do acute ulcerative and nonulcerative blepharitis differ?

21.2: Bacterial Infections of the Skin and Eyes

Multiple Choice

Staphylococcus aureus is most often associated with being

A. coagulase-positive.
B. coagulase-negative.
C. catalase-negative.
D. gram-negative

A

M protein is produced by

A. Pseudomonas aeruginosa
B. Staphylococcus aureus
C. Propionibacterium acnes
D. Streptococcus pyogenes

D

___________ is a major cause of preventable blindness that can be reduced through improved sanitation.

A. Ophthalmia neonatorum
B. Keratitis
C. Trachoma
D. Cutaneous anthrax

C

Which species is frequently associated with nosocomial infections transmitted via medical devices inserted into the body?

A. Staphylococcus epidermidis
B. Streptococcus pyogenes
C. Proproniobacterium acnes
D. Bacillus anthracis

A

Fill in the Blank

A purulent wound produces ________.

pus

Short Answer

How are leukocidins associated with pus production?

What is a good first test to distinguish streptococcal infections from staphylococcal infections?

21.3: Viral Infections of the Skin and Eyes

Multiple Choice

Warts are caused by

A. human papillomavirus.
B. herpes simplex virus.
C. adenoviruses.
D. parvovirus B19.

A

Which of these viruses can spread to the eye to cause a form of keratitis?

A. human papillomavirus
B. herpes simplex virus 1
C. parvovirus 19
D. circoviruses

B

Cold sores are associated with:

A. human papillomavirus
B. roseola
C. herpes simplex viruses
D. human herpesvirus 6

C

Which disease is usually self-limiting but is most commonly treated with ganciclovir if medical treatment is needed?

A. roseola
B. oral herpes
C. papillomas
D. viral conjunctivitis

A

Adenoviruses can cause:

A.viral conjunctivitis
B. herpetic conjunctivitis
C. papillomas
D. oral herpes

A

Fill in the Blank

Human herpesvirus 6 is the causative agent of ________.

roseola

Short Answer

Compare and contrast bacterial and viral conjunctivitis.

21.4: Mycoses of the Skin and Eyes

Multiple Choice

___________ is a superficial fungal infection found on the head.

A. Tinea cruris
B. Tinea capitis
C. Tinea pedis
D. Tinea corporis

B

For what purpose would a health-care professional use a Wood’s lamp for a suspected case of ringworm?

A. to prevent the rash from spreading
B. to kill the fungus
C. to visualize the fungus
D. to examine the fungus microscopically

C

Sabouraud dextrose agar CC is selective for:

A. all fungi
B. non-saprophytic fungi
C. bacteria
D. viruses

B

The first-line recommended treatment for sporotrichosis is:

A. itraconazole
B. clindamycin
C. amphotericin
D. nystatin

A

Fill in the Blank

The most common subcutaneous mycosis in temperate regions is ________.

sporotrichosis

Short Answer

What yeasts commonly cause opportunistic infections?

Critical Thinking

What steps might you recommend to a patient for reducing the risk of developing a fungal infection of the toenails?

21.5: Protozoan and Helminthic Infections of the Eyes

Multiple Choice

Which of the following is most likely to cause an Acanthamoeba infection?

A. swimming in a lake while wearing contact lenses
B. being bitten by deerflies in Central Africa
C. living environments in a college dormitory with communal showers
D. participating in a contact sport such as wrestling

A

The parasitic Loa loa worm can cause great pain when it:

A. moves through the bloodstream
B. exits through the skin of the foot
C. travels through the conjunctiva
D. enters the digestive tract

C

A patient tests positive for Loa loa antibodies. What does this test indicate?

A. The individual was exposed to Loa loa at some point.
B. The individual is currently suffering from loiasis.
C. The individual has never been exposed to Loa loa.
D. The individual is immunosuppressed.

A

________ is commonly treated with a combination of chlorhexidine and polyhexamethylene biguanide.

A. Acanthamoeba keratitis
B. Sporotrichosis
C. Candidiasis
D. Loiasis

A

Fill in the Blank

Eye worm is another name for ________.

loiasis

The ________ is the part of the eye that is damaged due to Acanthamoeba keratitis.

cornea

Critical Thinking

Why might a traveler to a region with Loa loa worm have a greater risk of serious infection compared with people who live in the region?

What preventative actions might you recommend to a patient traveling to a region where loiasis is endemic?