Dermatology Quiz and Case Discussion
From The Child's Doctor, Fall 2006
- Anthony J. Mancini, MD
- Head, Dermatology, Ann & Robert H. Lurie Children's Hospital of Chicago; Professor of Pediatrics and Dermatology, Northwestern University Feinberg School of Medicine
- Disclosure: Dr. Mancini has no industry relationships to disclose. He refers to cantharidin, podophyllin, podophylotoxin, salicylic acid, phenol, potassium hydroxide, topical retinoids, silver nitrate, trichloroacetic acid, intralesional interferon, oral cimetidine, imiquimod cream, and cidofovir. These products are not labeled for use in discussion, but are well documented in the literature for this use.
- Leslie P. Lawley, MD
- Fellow, Dermatology, Children's Memorial Hospital
- Disclosure: Dr. Lawley has no industry relationships to disclose. She refers to cantharidin, podophyllin, podophylotoxin, salicylic acid, phenol, potassium hydroxide, topical retinoids, silver nitrate, trichloroacetic acid, intralesional interferon, oral cimetidine, imiquimod cream, and cidofovir. These products are not labeled for use in discussion, but are well documented in the literature for this use.
Other Disclosure Information
At the conclusion of this activity, participants will be able
- Recognize the lesions shown in the photographs and
described in the vignettes
- Discuss differential diagnosis
- Describe appropriate treatment
1. An otherwise-healthy 8-year-old
boy presents for evaluation of multiple papules on his arms, legs (Figure 1) and
trunk. He has developed over 50 of these lesions, which are asymptomatic, over the
last 4-5 months.
The most likely etiology is:
A. Herpes simplex virus
C. Varicella zoster virus
D. Human papilloma virus
2. A 2-year-old girl
presents with similar skin lesions on her trunk and extremities, which have been
present for 8 months. Her mother reports that over the last 2
weeks, many of these previously flesh-colored papules have become acutely red (Figure 2) and
increased in size. There is no pain, tenderness or discharge, and she has
had no fever or other symptoms.
The most appropriate therapeutic approach to this patient is:
A. Topical corticosteroid ointment
B. Systemic antibiotic therapy
C. Reassurance and watchful waiting
D. Skin culture and topical antibiotic therapy
E. Manual curettage
3. A 7-year-old female is referred for evaluation of
an itchy rash. It has been present for 6 weeks, involves the arms, trunk and
legs (Figure 3), and was preceded by several flesh-colored papules in
the same distribution.
The appropriate treatment is:
A. Topical corticosteroid ointment followed by a return visit for
treatment of the papules
B. Topical imiquimod cream and cryotherapy
C. Reassurance and watchful waiting
D. Skin culture and topical antibiotic therapy
E. Oral cimetidine at high-dose for 8 weeks
Answers: 1B, 2C, 3A
Molluscum contagiosum is a common infection of the skin seen most often
in school-aged children, and caused by the molluscum contagiosum virus (MCV), a
poxvirus. In a recent US
study two-thirds of patients were less than 8 years old. In adults, molluscum
contagiosum is often associated with sexual transmission and/or
immunodeficiency. These associations are rare in children, in whom MCV is likely
spread through innocent skin-to-skin contact. A relationship between swimming
pool exposure and development of molluscum contagiosum has been suggested.[2,3]
Four different genotypes of MCV have been isolated; infection with MCV type 1
results in the majority of pediatric cases of molluscum
Clinically, flesh-colored, pearly dome-shaped papules are observed upon
examination. A central area of umbilication may or may not be present. Molluscum
lesions may occur anywhere on the body, but are most often seen on the trunk in
patients less than 5 years of age and on the extremities in those over 5 years
of age. The antecubital and popliteal fossae, axillae, and groin are common
sites of involvement, and autoinoculation is frequently noted in these areas,
felt to be secondary to skin-to-skin contact. Occasionally, an associated
dermatitis surrounding a group of molluscum lesions is present, and has been
termed “molluscum dermatitis.” The resultant scratching in these areas may
propagate autoinoculation, with the development of additional lesions. Even
though MCV is typically not associated with immunodeficiency in children, it may
take 18 to 24 months for the host immune system to react against the virus. Once
this occurs, individual lesions often become acutely erythematous and edematous,
a clinical sign heralding spontaneous resolution, which is usually complete
within 2 to 3 weeks.
Molluscum contagiosum is typically diagnosed on a clinical basis. If
there is a question, curette of an individual lesion may be performed, and the
contents smeared onto a glass slide. Microscopic evaluation following
application of an appropriate stain (Wright, Gram, Giemsa or Papanicolaou) will
reveal viral inclusion (also known as Henderson-Patterson) bodies. Skin
biopsy is rarely indicated, but will also reveal the characteristic viral
inclusions on hematoxylin and eosin-stained sections.
The differential diagnosis of molluscum contagiosum may be broad, and can
include herpes simplex infection, verruca vulgaris, syringoma (and other adnexal
tumors), pyoderma, papular granuloma annulare, condyloma acuminatum, cutaneous
Cryptococcus infection, histoplasmosis, keratoacanthoma, epidermal inclusion
cyst, basal cell carcinoma, neurilemmoma, or pyogenic granuloma. The lesions
of herpes simplex infection are vesicular and painful, and cluster on an
erythematous base. Verruca vulgaris (common wart) presents with hyperkeratosis
and verrucous surface changes, and lack central umbilication. Condylomata
acuminata (anogenital warts) may be difficult to distinguish, but usually show
some verrucous changes and also lack central umbilication. Pyoderma usually
presents with erythema, crusting and purulent discharge. Adnexal tumors,
keratoacanthoma, and basal cell carcinoma are very rare in children, and may
occasionally mimic the flesh-colored popular nature of molluscum. These lesions,
along with those of papular granuloma annulare and neurilemmoma, can be easily
differentiated on histologic evaluation. Pyogenic granuloma presents as a
vascular papule, which is often accompanied by surface erosion, compressibility,
and a history of bleeding. Cutaneous cryptococcosis and histoplasmosis usually
occur in the setting of immunodeficiency.
While treatment of molluscum is not necessary, many parents are concerned
about the appearance, contagiousness, or associated symptoms (ie, itching in the
presence of molluscum dermatitis), and request intervention. Since the
natural history is one of eventual spontaneous resolution, treatment for these
lesions should be as painless as possible and entail no increased risk of
scarring. Therapeutic options are multiple, and have included cantharidin (Asian
blister beetle extract), podophyllin, podophylotoxin, curettage, cryotherapy,
salicylic acid, phenol, potassium hydroxide, topical retinoids, silver nitrate,
trichloroacetic acid, intralesional interferon, oral cimetidine, tape stripping,
manual core extraction, electrodessication, carbon dioxide laser, pulsed dye
laser, imiquimod, and cidofovir.[7,8] The success of most of these therapies is
varied and inconsistent.
Cantharidin is an extremely safe, effective and well-tolerated treatment
when applied sparingly (with the blunt end of a wooden applicator stick) to
non-facial, non-fold area lesions. It does result in minor blistering, and
mild discomfort may occur in the first 24 hours following treatment. Up to 30
lesions are treated in 1 visit, with repeat visits scheduled at 3 to 8 week
intervals as necessary. Parents must be thoroughly educated in rinsing the
treated areas (usually in 4 hours) and in expecting blistering prior to healing.
When an associated molluscum dermatitis is present, it should be treated with a
topical corticosteroid cream or ointment in an attempt to alleviate itching and
help prevent autoinoculation and secondary bacterial infection.
Facial lesions pose a therapeutic challenge, as cantharidin is not safe
for use in this setting. The strategies most often employed for facial lesions
include watchful waiting, topical retinoids, imiquimod cream, or light
cryotherapy (in patients who can tolerate this treatment). Surgical removal or
curettage is occasionally necessary for larger eyelid lesions.
R E F E R E N C E S
[1.] Dohil MA, et al. The epidemiology of molluscum contagiosum in
children. J Am Acad Dermatol 2006;54(1):47-54.
[2.] Braue A, et al. Epidemiology and impact of childhood molluscum
contagiosum: A case series and critical review of the literature. Pediatr
[3.] Choong KY, Roberts LJ. Molluscum contagiosum, swimming and bathing:
A clinical analysis. Australas J Dermatol 1999;40(2):89-92.
[4.] Gottlieb SL, Myskowski PL. Molluscum contagiosum. Int J Dermatol
[5.] Paller AS, Mancini AJ. Hurwitz Clinical Pediatric Dermatology. 3rd
ed. Philidelphia: Sanders; 2006:412-415.
[6.] Tyring S. Mucocutaneous Manifestations of Viral Disease. New York: Marcel Dekkor
[7.] Bolognia J, Jorizzo JL, Rapini RP. eds. Dermatology. Edinburgh: Mosby;
[8.] Leslie KS, Dootson G, Sterling JC.
Topical salicylic acid gel as a treatment for molluscum contagiosum in children.
J Dermatolog Treat 2005;16(5-6):336-340.
[9.] Silverberg NB, Sidbury R, Mancini AJ. Childhood molluscum
contagiosum: Experience with cantharidin therapy in 300 patients. J Am Acad
[10.] Brown J, et al. Childhood molluscum contagiosum. Int J Dermatol