Molluscum

Question 1

In molluscum contagiosum? most commonly affected?

Answer 1

children
sexually active adults
athletes participating in contact sports
individuals with impaired cellular immunity

Question 2

Molluscum contagiosum transmission?

Answer 2

Common benign cutaneous viral infection

Skin to skin contact

Question 3

What age group in molluscum?

Answer 3

before the age of 14 years old

median age of 5 years

Question 4

MC lesions?

Answer 4

Mainly limited to the skin, but rarely develop on mucosal surfaces, including the eye

Question 5

In children lesions are usually found where?

Answer 5

exposed areas

Question 6

In adults lesions are usually found where?

Answer 6

many cases are limited to the genital area, suggesting sexual transmission
In adults lesions typically develop in the genital area

Question 7

MC infections are more common in individuals infected with?

Answer 7

HIV

Question 8

Transmission in molluscum occur via?

Answer 8

direct skin or mucous membrane contact
fomites
Bath towels
swimming pools
public or shared baths
autoinoculation
koebnerization 
vertical transmission from mother to neonate during the intrapartum period

Question 9

where does MC live?

Answer 9

in the epidermis

does NOT remain latent in the body after the cutaneous lesions have cleared

Question 10

MC often presents as?

Answer 10

Small pink, pearly, or skin-colored papules that enlarge to 2 to 5 mm in size?

Question 11

Lesions may have a? in molluscum

Answer 11

Central dell or umbilication from which a white curd-like substance containing the virus can be expressed with pressure
Lesions may be grouped in clusters or appear in a linear array

Question 12

where does children usually develop MC?

Answer 12

children usually develop multiple papules,

often in exposed sites like the face and extremities or intertriginous sites, such as the axillae and popliteal fossae

Question 13

does molluscum contagiosum result from koebnerization or development of lesions at sites of trauma?

Answer 13

Lesions may be grouped in clusters or appear in a linear array

Question 14

How big can molluscum develop in immunosuppressed patients?

Answer 14

May develop giant molluscum as large as 2.5 cm in diameter

Question 15

Is molluscum associated with systemic complications?

Answer 15

NO.

Question 16

What are the complications of MC?

Answer 16

• pruritus (particularly in those patients with underlying atopic dermatitis)
• Chronic conjunctivitis and punctate keratitis may develop in patients with eyelid lesions)
• secondary bacterial infection can occur, particularly if patients scratch their lesions

Question 17

How many percent of patients develop Molluscum dermatitis?

Answer 17

19 to 39% of children develop this.

Question 18

Describe molluscum dermatitis

Answer 18

erythematous, eczematous dermatitis surrounding their molluscum lesions

Question 19

Molluscum dermatitis is more common in children with?

Answer 19

atopic dermatitis

roughly half of children with both atopic dermatitis and MC develop molluscum dermatitis

Question 20

The development of inflamed MC lesions suggest what?

Answer 20

A robust immune response and tends to be associated with a subsequent decline in the number of lesions

Question 21

Does a small subset of individuals with MC develop a Gianotti-Crosti-like reaction?

Answer 21

Yes. A small subset of individuals with MC develop a Gianotti-Crosti-like reaction consisting of

• pruritic, monomorphous, edematous, erythematous papules or papulovesicles
• centered on the elbows and knees, which lasts for several weeks
• eruption tends to be followed by reduction in the number of MC lesions and may be considered a favorable prognostic sign

Question 22

What is the etiologic agent of Molluscum Contagiosum?

Answer 22

Molluscum contagiosum virus

Question 23

Describe the MC virus.

Answer 23

It is a large, brick-shaped DSDNA poxvirus

Question 24

What strain of MC virus is responsible for 98% of the disease?

Answer 24

MC virus genotype 1

Question 25

MC virus genotype 2 is primarily seen in?

Answer 25

Adults and immunocompromised individuals

Most commonly transmitted by sexual contact.

Question 26

How long is the incubation period of the virus?

Answer 26

approximately 2-6 weeks.

Question 27

Where does MC virus replicate?

Answer 27

in the cytoplasm of epithelial cells.

Question 28

Where does viral inclusion bodes (Henderson Paterson bodies) develop?

Answer 28

In the basal layer of the epidermis.

They enlarge as cells rise through the epidermis, pushing cellular organelles against the sides of the cell.

Question 29

What happens whens there is proliferation and enlargement of the virion packed cells?

Answer 29

Disintegration of the stratum corneum and the formation of a dimple-like ostium through which the virions are released when the inclusion bodies rupture

Question 30

Can molluscum lesions persist for a long time without significant inflammatory cell infiltration?

Answer 30

yes because MC virus possess multiple genes that impede host response

a) coding for a homolog of a major histocompatibility class I heavy chain, which may interfere with antigen presentation
b) a chemokine homolog that inhibits chemotaxis
c) a protein that inhibits apoptosis by preventing activation of the death effector domain of caspase 8
d) glutathione peroxidase homolog that prevents apoptosis in cells damaged by UV radiation and hydrogen peroxide

Question 31

Eventually the immune system detects the MC virus and mounts a localized response involving what?

Answer 31

1. plamacytoid dendritic cells
2. interferon-induced dendritic cells
3. natural killer cells
4. cytotoxic T lymphocytes

Ultimately clearing the infection…