Molluscum Contagiosum

Question 1

Define Molluscum Contagiosum

Answer 1

Skin condition caused by the molluscum contagiosum virus, causing cutaneous lesions that appear as pearl-like, smooth papules, which are umbilicated

Question 2

What is the difference between molluscum contagiosum, giant molluscum and inflamed molluscum

Answer 2

Molluscum contagiosum = Common molluscum that are pearly papules with a central dell, usually over the chest wall and axillae in children, and in the groin and inner thighs in adults.

Giant molluscum = Lesions are usually smooth papules or nodules without central dell and are present in the inter-gluteal area or on the sole of the foot.

Inflamed molluscum = These lesions manifest erythema, swelling, and pruritus, typically as a marker of immune response to the lesions.

Question 3

Aetiology of Molluscum contagiosum

Answer 3

Molluscum contagiosum virus - a ubiquitous poxvirus that escapes immune destruction for months to years

The virus infects keratinocytes and mucosa, causing papular lesions

3 types:

• MCV 1 and 1v: children due to child-to-child contact or fomites
• MCV 2: sexually-transmitted noted in the groin in adults, generalised in immunocompromised patients
• MCV 3: rare

Question 4

What is the infectious/clinical course for Molluscum contagiosum

Answer 4

MCV infects the skin and causes lesion appearance within a few days and up to 6 weeks later.
The virus induces abnormal keratinocyte growth
The natural course of infection is spontaneous clearance in 2 to 4 years
Clearance requires the appearance of anti-molluscum antibodies and cellular immunity.

Question 5

Risk factors for Molluscum Contagiosum

Answer 5

Close contact with infected individual (children)
Sexual contact with an infected individual
HIV infection
Tropical climate
Swimming
Atopic dermatitis

Question 6

Symptoms of Molluscum Contagiosum

Answer 6

Skin rash that looks like little dots on the skin (May be on the face or groin (not treated in children))
Pruritus
Sleep disturbance associated with pruritus

Question 7

Signs of Molluscum Contagiosum on examination

Answer 7

Pearly papule with central dell (characteristic appearance, >50 lesions suggests immunosuppression)
Surrounding erythema
Atopic dermatitis

Question 8

Investigations for Molluscum Contagiosum

Answer 8

Haematoxylin and eosin staining: Henderson-Patterson bodies
Tzanck stain: purple ovoid keratinocytes

HIV testing: in refractory disease

Curettage biopsy: rare