Microbiology - Moffat - Viral Infections of the Skin Flashcards Preview

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Flashcards in Microbiology - Moffat - Viral Infections of the Skin Deck (76):
1

Stomatitis means:

inflammation of the nose and mouth
is herpes simplex type 1

2

Dewdrop on rosepetal rash;
aerosol transmission;
highly contagious

Herpes - alpha
Varicella - primary infection

*dewdrop on rosepetal rash for all HSVs

3

What is the treatment for oral hairy leukoplakia?

Treat the underlying reason for immunodeficiency
(EBV reactivation)
EBV is HHV-4

4

Faint, smooth, flat rash in children

Primary CMV
CMV is HHV-5

5

HHV-6b and HHV-7;
Endogenous rash in children
T-cell infection and activation --> rash
Virus shed in saliva

Roseola
Day 1 and 2 - fever
Day 3 - fever gone, rash

6

T/F: CMV mononucleosis is very similar to infections mononucleosis caused by EBV (when symptoms of CMV occur).

True
Lack of sore throat and petechial rash differentiate

7

In what popoulations is HHV-8 seen?

Kaposi's sarcoma
African Mediterranean, homosexual populations
found in B cells and endothelial cells
**when it manifests, it is a secondary manifestation

8

Vaccinia virus is the live virus used the the vaccine to prevent against:

Smallpox (Variola) and monkeypox

9

Most contagious virus that we know:

Measles - Rubeola
single-stranded, negative-sense, enveloped RNA virus

10

German measles;
When pregnant women get infected, can cause massive congenital defects

Rubella virus

deafness, jaundice, blindness...

11

What does exanthem mean?

Eruptive disease, infectious rash

12

What does macular mean?

Flat, discolored patch

13

What does papular mean?

Raised, discolored patch

14

Herpesvirsues establish latency where?

Neurons or lymphocytes
Latency established during primary infection
Asymptomatic shedding can occur at any time

15

HSV-1 latency occurs where?

Trigeminal nerve DRG

16

What is one of the more dangerous complications of HSV-1 and HSV-2?

HSV keratitis, corneal ulcers and scarring
infiltration of T-cells that destroy the cornea

17

What is Herpetic Whitlow?

HSV-1 on hands
Dentists, hospital workers, wrestlers
recurs on hands, back and legs

18

Aseptic meningitis is a complication of:

HSV

19

Complications of VZV

dissemination to brain;
visceral infection;
pneumonitis;
bacterial infections of lesions

20

Complications of Zoster

keratitis;
retinitis;
Bell's Palsy;
postherpetic neuralgia

21

What is HZO?

Herpes Zoster Ophthalmicus
30% of zoster affects the face
can destroy the retina, blindness
extremely painful, long lasting pain common

22

What kind of vaccine is the VZV vaccine?

Live, attenuated
Varivax - varicella
Zostavax - to prevent zoster (14x higher dose than varivax)

23

What cells does EBV infect?

B cells and epithelia or oropharynx
**sore throat**
EBV remains latent in a small # of B cells

24

How does the rash in rubella spread?

Starts on face and spreads downward
children, immigrant populations common

25

small, naked, ssRNA Enterovirus;
red-ringed blisters and ulcers on tonsils and soft palate;
hemmorhagic conjunctivitis;
hand, foot and mouth...

Cocksackie virus

26

HPV lesions should be differentited from what other viral lesions?

Molluscum Contagiosum virus (a poxvirus)

27

Smallpox vaccination provides cross-protection from what other virus?

Monkeypox virus
Issue in Africa where smallpox vaccinations are not given

28

Pearly lesions, raised, umbilicated;
Pox virus;
transmission by skin-skin contact or fomites;
higher incidence in children and HIV patients

Molluscum Contagiosum virus

29

The natural host for monkeypox virus is:

Squirrel, but human-human transmission is increasing bc no smallpox vaccinations being given

30

Variola Virus causes:

smallpox
extinct
massive and lethal epidemics
death in 2nd week from overwhelming infection

31

What is Vaccinia virus?

Variola and other poxviruses combined to make smallpox vaccine
Live vaccine, given to military

32

The vaccinia vaccine is contraindicated for:

people with eczema

33

Paramyxovirus, envelopes, negative strand RNA;
cough, conjunctivitis, fever, rash
Koplick's spots - small red spot with bluish centers on buccal mucosa

Measles virus

34

togavirus, enveloped, positive strand RNA
aerosol spread
respiratory virus
rash spreads from head downward;
congenital infections are severe

Rubella virus aka German measles

35

Parvovirus can cause what kind of rash?

Slapped face appearing rash in a child

36

T/F: Infection in young children by EBV is often asymptomatic.

True

37

Vaccination for variola virus (smallpox) can cause what symptom? associated with what virus?

Red and swollen skin (eye lids) with pustular vesicles

Caused by vaccinia virus which is used to vaccinate against small pox

38

How is primary varicella-zoster virus tramissted?

Where is the virus maintained in dormancy?

What is the appearance of the rash?

What is the treatment/prevention?

What are some complications?

If the virus reactivates what does it lead to?

aerosol transmission - highly contageous

Dorsal root ganglia

"Dew drops on rose petals" - hundreds on face and trunk

vaccine (Varivax), acyclovir,
Foscarnet

visceral infection, dissemination to brain,
pneumonitis, bacterial infection of lesions

39

If varicella-zoster is reactivated later in life what is this and how does it present? Treatment? Complications?

Herpes zoster
- Prodrome: burning, itching, tingling
- Outbreak occurs along a single dermatome
- Vesicular lesions are extremely painful, pruritic
- More common in the elderly and immunocompromised
- Treat with acyclovir and derivatives
- Complications include keratitis, retinitis, Bell’s palsy,
postherpetic neuralgia

40

Prodrome: itching, tingling at lesion site a day before outbreak.
- Vesicular lesions appear on labia, penis, anus, mouth, etc.
- Lesions are contagious, but shedding and transmission can occur without symptoms.
- Frequency of recurrences is highly individual; ranges from never to monthly.
- Prophylactic antiviral treatment can reduce recurrences and thus transmission.
- Infection is also painful emotionally: heavy stigma associated
- Moderate risk for perinatal infection

HSV-2: Recurrent genital herpes

41

Extensive vesicular, pustular, or erythematous lesions lesions on penis, labia, anus (oral
and ocular possible)
- Other symptoms:, pain, itching, fever, malaise, headache
- _____ infections are usually but not always below the waist
- Antiviral treatment is important to shorten acute infection, prevent spread to brain

- Double infections with ____and ____ are common
- Highest risk for congenital infections (mother to fetus/neonate)

HSV-2: Primary genital herpes

42

Primary HSV-1 or HSV-2 of non-mucosal sites, acquired by
direct contact
- Putting bare hands into others’ mouths is a risk factor
- Dentists, hospital workers, and wrestlers (!) are susceptible
- Recurrences at unusual sites: hands, legs, back
- Treatment: acyclovir and derivatives
- Prevention: gloves

Herpetic Whitlow

43

Primary infection in the eye often occurs at birth from vaginal
mucosa
- Caused by recurrence of HSV-1 or HSV-2
- Chronic HSV keratitis can cause corneal scarring and vision loss
- Disease is mediated by infiltration of T cells that destroy the
cornea
- Treatment: Antivirals are important to prevent corneal damage,
corneal transplant may be needed

HSV keratitis and corneal scarring

44

- 20% of seropositive people have recurrent lesions on lips, eyes, or inside mouth
- Cold sores, “canker sores”, fever blisters
- Recurrences are triggered by fever, UV exposure, hormones, stress, physical trauma, etc.
- Lesions are contagious, secretions can spread virus without symptoms
- Treatment:
o Acyclovir, Zovirax, Valtrex, Famvir
o Use as needed for outbreaks or prophylactically to prevent recurrences

Recurrent HSV-1: herpes labialis (cold sores)

45

- Usually occurs in childhood
- Spread by close contact with active lesions or asymptomatic
shedding
- Lesions on mouth, face, nose, eyes, etc.
- Latency in dorsal root ganglia neurons
- HSV-1 infections are usually above the waist, can be genital
- Treatment: Oral acyclovir (Zovirax) or derivatives
- 50-80% of U.S. population is seropositive

Primary Herpes simplex virus Type 1

46

Can herpesvirus be transmitted if the infected person is asymptomatic?

Yes! Viral shedding during latency can occur at any time and cause transmission to uninfected person

47

What is HHV6/7?

Roseola virus

48

What is associated with coxackie virus?

Hand foot and mouth syndrome

49

__ infects B cells and epithelia of oropharynx
- restricted to humans, 90% of population is
infected by adulthood
- Childhood infections are often asymptomatic
- Older teens often have “Mono”
- 170,000 cases of IM per year, 15% hospitalized

Epstein Barr Virus: primary infectious
mononucleosis

50

Epithelial overgrowth caused by_____
– nonpainful hairy or feathery lesions on the tongue or buccal mucosa
– Associated with HIV infection, transplantation, chemotherapy, etc.

EBV caused Oral hairy leukoplakia

51

Primary __ infection is usually asymptomatic and acquired in childhood
- When symptoms occur:
• ___ mononucleosis is very similar to IM caused by EBV
• Lack of sore throat and presence of petechial rash and jaundice differentiate from
EBV

Cytomegalovirus: primary infection

52

Caused by HHV6b and HHV7; no known disease
linked to HHV6a
- HHV6, 7 infect CD4+ T cells, site of latency
- Transmitted in saliva
- By age 2, >90% of children have had roseola twice
- 3-day illness of high fever, followed by a faint rash
on the trunk
- Many infants are mistakenly given antibiotics for a
suspected infection, then the rash is attributed to a drug allergy

Roseola: Exanthem subitum

53

Primary infection: no known disease
- ____ is prevalent in African, Mediterranean, and homosexual
populations
- evidence for sexual transmission
- ___ is found in B cells and endothelial cells. Probable site of latency.

Kaposi’s Sarcoma Herpesvirus: KSHV, HHV8

54

Cancers associated with KSHV/HHV8

- Kaposi’s sarcoma
- body cavity-based lymphomas (BCBLs)
- Castleman's disease hyperplastic lymphadenopathy

55

- Small, naked DNA virus
- HPV infects skin, genitals, cervix, anus, and mucosa
- Spread by direct contact
- Treat with chemical or surgical removal
- Gardasil: vaccine for young women, now recommended for boys at age 11
- Differentiate from lesions caused by molluscum contagiosum virus

Human Papilloma Virus (HPV)

56

Pearly appearance of the vesicles. The lack of inflammation makes
them look pale and shiny.
- Poxvirus – large, enveloped DNA virus
- Lesions are pearly, flesh-colored, raised, umbilicated
o Occur anywhere on the body in children
o Anogenital area in sexually active adults
o Occasionally, a single “giant molluscum” nodule may occur (10 mm).
o Lesions rarely appear on the palms, soles, mucosa, face or eyes
- Transmission by skin-skin contact or by fomites, eg tattooing, wrestling, towels.
- Disease incidence is 2-8%
o most common in school-age children.
o Higher incidence in HIV+ population (5-20%).
- Treatments:
o Surgery, cryotherapy or chemicals
o Topical treatment
with Cidofovir is
promising

Molluscum Contagiousum Virus (MCV)

57

- Historical cause of massive, lethal epidemics
- Fever, severe aching pains and prostration
- 2 to 3 days later, an umbilicated papular rash over the face and extremities
- Rash stages: papular, vesicular then pustular, scabs leave pitted scars
- Death usually occurs during the second week from overwhelming infection
- Treatment: supportive care, vaccination
- Eradicated from the wild in 1979 following worldwide vaccination program

Variola Virus (Smallpox)

58

Auto-inoculation from the arm to the eyes
- Generalized vaccinia: virus disseminates through body
- Eczema vaccinatum: this vaccine is contraindicated for anyone with eczema!
- Progressive vaccinia: Vaccinia necrosum or gangrenosum
o Occurs in immunocompromised patients
o Treatment includes Cidofovir and VIG (Vaccinia Immune Globulin)

Vaccinia virus

59

– Paramyxovirus, enveloped, negative strand RNA
– Contagious during incubation period
– Symptoms: cough, conjunctivitis, fever, rash
– Koplik’s spots: small red spots with bluish centers on buccal mucosa
– Outbreaks in UK, Africa, Asia (In 2000, 1603 measles cases in Ireland)
– ~500,000 cases annually worldwide

Measles virus

60

- Togavirus, enveloped, positive strand RNA
- Respiratory virus, aerosol spread
- Maculopapular rash, lymphadenopathy, arthralgia
- Congenital infections are severe
- Treatment: none
- Prevention: MMR vaccine
o No association with autism
o “Herd” immunity is crucial to prevent outbreaks

Rubella virus (German measles)

61

1. Reactivation of Herpes Simplex Virus Type 1 (HSV-1) is characterized by:
a. Restriction to the oral mucosal.
b. Protection from double infections with HSV-2.
c. Lytic replication in salivary glands.
d. Viral shedding from vesicular or asymptomatic lesions.
e. Oral hairy leukoplakia.

D

62

2. Reactivation of Varicella Zoster Virus (VZV) is characterized by:
a. Lack of effective antiviral therapy.
b. Lymphadenopathy.
c. Giving the live-attenuated vaccine (Varivax) to the elderly.
d. Experiencing stress or exposure to ultraviolet light.
e. A painful, unilateral rash.

E

63

3. Primary infection with cytomegalovirus (CMV) is characterized by:
a. High fever followed 2 days later by a lacey rash on the chest.
b. Establishment of latency in neurons.
c. Various B cell lymphomas.
d. Risk of congenital CMV syndrome in neonates.
e. Retinitis and progressive vision loss.

D

64

4. What is the best explanation for the fact that 90% of the U.S. population is infected with
Epstein Barr Virus (EBV) by adulthood, but many fewer people report having had infectious
mononucleosis (IM)?
a. The virus is spread by sexual contact.
b. The virus is shed in breast milk.
c. Infection in young children is often asymptomatic.
d. The degree of symptoms is inversely correlated with the strength of the cellular
immune response.
e. The tonsilar exudate is easy to confuse with strep throat.

C

65

5. One advantage of using vaccinia virus to immunize against smallpox and monkeypox is:
a. The consequences of dissemination or adverse reactions are minor.
b. The vaccine is heat-killed.
c. The immune response to vaccinia is robust and long lasting.
d. The vaccinia strain of poxvirus is restricted to replication in humans.
e. None of the above.

C

66

6. Molluscum contagiosum virus is:
a. Treated by excision or cryotherapy.
b. The cause of impetigo.
c. Rapidly progressing and associated with inflammation at the lesion site.
d. Easily spread by aerosol droplets.
e. Most common in the elderly.

A

67

7. Which characteristic of smallpox was most critical for its eradication in the wild:
A. Viral replication solely in the cytoplasm.
B. Durability on fomites.
C. Resemblance to varicella.
D. Ability to downmodulate the immune response.
E. No animal or environmental reservoir.

E

68

8.Which of the following is not a characteristic of herpesvirus latency:
A. The virus genome is maintained in the cell nucleus.
B. Reactivation can occur months to years after acute infection.
C. Latently infected cells appear normal.
D. Expression of viral mRNA and protein is turned off.
E. Immune detection is minimal.

D

69

9. The alphaherpesviruses HSV-1, HSV-2 and VZV are closely related. Which feature is
common to all three viruses:
A. Infection with one virus protects from infection with the others.
B. Asymptomatic shedding is rare.
C. They are susceptible to acyclovir and its derivatives.
D. Primary infection is mild or unnoticed.
E. Latency is established in B cells.

C

70

10. Both Epstein Barr Virus and cytomegalovirus can cause mononucleosis. What feature is
unique to CMV?
A. Hepatosplenomegaly
B. Association with B cell lymphomas
C. Petechial rash
D. Virus is shed in saliva
E. Sore throat

C

71

11. HHV-6B and HHV-7 cause roseola in infants and toddlers. How is this disease acquired?
A. Breastmilk
B. Skin rash
C. Cold sores
D. Fecal-oral
E. Saliva

E

72

12. The alphaherpesviruses HSV-1, HSV-2 and VZV are closely related and all 3 may cause
lesions on the face. What features are most characteristic of the disease herpes zoster?
A. Corneal scarring due to chronic keratitis and T cell responses to viral antigens
B. Nonpainful, white hairy lesions on the tongue and buccal mucosal
C. Vesicular and crusted lesions on the lips and/or oral mucosal
D. Vesicles overlying erythematous papules scattered on face, trunk, and extremities
E. Painful vesicles and crusts erupting along a single dermatome

E

73

13. Choose the correct statement about the poxvirus molluscum contagiosum virus (MCV).
A. MCV lesions appear as umbilicated pustules that are removed by excision or
cryotherapy
B. A live vaccine for MCV is scraped into the skin using a bifurcated needle
C. MCV was used in the 18th century variolation process to protect against smallpox
D. MCV is spread from rodents to primates and humans
E. MCV is most common in the elderly

A

74

14. When varicella-zoster virus reactivates, it causes an infectious rash along a dermatome. If
the virus is transmitted to a naïve host, what disease does it cause?
A. Varicella.
B. Hepatosplenomegaly and a petechial rash.
C. Herpangina.
D. Primary infectious mononucleosis.
E. Post herpetic neuralgia.

A

75

15. Virus infections that result in skin rashes, congenital infections, and CNS diseases are all
likely to share what main feature?
A. Indirect pathology caused by inflammation.
B. Dissemination by viremia.
C. Asymptomatic recurrences and shedding.
D. Neurotropism, and possibly neurovirulence.
E. Small, naked virions with positive-strand RNA genomes.

B

76

A. Herpes simplex virus Type 1 (HSV-1)
B. Herpes simplex virus Type 2 (HSV-2)
C. Varicella zoster virus
D. Epstein Barr virus (EBV)
E. Cytomegalovirus (HCMV)
F. HHV-6B or HHV-7
G. Kaposi’s Sarcoma Herpesvirus (KSHV, HHV-8)
H. Variola virus
I. Vaccinia virus
J. Molluscum contagiosum virus (MCV)
K. Monkey pox virus

select the most likely causative agent

1. A 16-month-old girl with a recent history of high fever and irritability presents with a
faint, lacey rash covering her trunk and neck.
2. A 5-year-old boy presents with a painless, vesicular rash under his left arm. There are a
dozen umbilicated papules scattered in a crop. His mother reports that he had chicken
pox in preschool two years ago.
3. A 23-year-old woman presents with vesicular, erythematous lesions on her right index
finger and palm. She reports her occupation as dental hygienist and says she has had no
recent contact with plants or skin irritants.
4. A 33-year-old man with Type 1 diabetes complains of floaters and blurred vision in his
right eye. He was given a kidney allograft 6 months prior and is on immunosuppressive
therapy.
5. A 25-year-old man presents with a severe eye infection. The right lid is swollen and
crusted with lesions. He reports that he is on a short leave from the US Army before his
unit is shipped overseas.
6. A 19-year-old woman presents with swollen cervical lymph nodes, fever, fatigue,
jaundice, and an enlarged liver. She reports that she is a premed college student and
volunteers in the hospital pediatric ward.


1, F; 2, J; 3, A; 4, E; 5, I; 6, E.