Diagnosis
Molluscum contagiosum
A benign contagious viral infection that causes characteristic skin lesions consisting of single or multiple, rounded, umbilicated, pink, waxy papules.
Also known as: Water warts
Etiology
Cause
Molluscum contagiosum virus (Poxviridae family)
Pathophysiology [vop]
Transmission
Skin trauma (shaving, atopic dermatitis)
Direct skin-to-skin contact: school, swimming pool, sports, sexually transmitted
Indirect skin contact: bath towels, sponges, and gymnasium equipment
In utero and prepartum transmissions (rare) --> congenital molluscum contagiosum
Incubation time: 2-6 weeks
The virus infects only keratinocytes (no systemic dissemination)
The virus produces proteins inhibiting human antiviral immunity, thus preventing the development of innate immunity response --> persistence of skin lesions
Complications [vop]
Inflammation or infection (cellulitis)
Irritation
Conjunctivitis if the lesions are on the eyelids
Abscess
Epidemiology
Incidence per 100.000 [qzs][rd9][w4d][f3n][shq][8u2][rhm]
Symptoms & findings
Symptoms
None listed.
Clinical findings
None listed.
Anamneses
None listed.
Localized findings
Approach
Clinical diagnosis with dermatoscopy: [qzs]
Lesion type: Umbilicated papules with a central caseous plug
Size: 2- to 5mm in diameter
Surface: Smooth
Color: Flesh-colored
Distribution: Individually or commonly in clusters on the face, trunk and extremities
Symptoms: Mostly asymptomatic, but may have pruritus.
Biopsy
Treatment
Self-limited and will resolve without therapy within 9 months [qzs]
Supportive and cosmetic treatment options: [qzs][rhq]
Cantharidin (topical)
Bichloracetic acid (topical)
Cimetidine (oral)
Cryotherapy
Curettage
Glycolic acid / Lactic acid (less effective)
Imiquimod cream
Podophyllotoxin cream
Potassium hydroxide 10–20%
Pulsed dye laser
Salicylic acid (topical)
Sinecatechin (topical)
Tretinoin (topical)
Trichloroacetic acid peel (topical)
Hydrogen peroxide
Silver nitrate
Differential diagnoses
Aspergillosis, Basal cell carcinoma, Chickenpox, Condyloma acuminatum, Cryptococcosis, Eccrine poroma, Epidermal cyst, Folliculitis, Foreign body granuloma, Granuloma annulare, Herpes simplex, Herpes zoster, Histoplasmosis, Kaposi sarcoma, Keratoacanthoma, Keratosis pilaris, Kyrle disease, Lichen planus, Milia, Nevus, Pyoderma gangrenosum, Pyogenic granuloma, Sporotrichosis, Verruca vulgaris
References
[1] Badri T, Gandhi GR. Molluscum Contagiosum. [Updated 2023 Mar 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441898/
[2] Hebert AA, Bhatia N, Del Rosso JQ. Molluscum Contagiosum: Epidemiology, Considerations, Treatment Options, and Therapeutic Gaps. J Clin Aesthet Dermatol. 2023 Aug;16(8 Suppl 1):S4-S11.
[3] McCollum AM, Holman RC, Hughes CM, Mehal JM, Folkema AM, Redd JT, Cheek JE, Damon IK, Reynolds MG. Molluscum contagiosum in a pediatric American Indian population: incidence and risk factors. PLoS One. 2014 Jul 29;9(7):e103419.
[4] Dohil MA, Lin P, Lee J, Lucky AW, Paller AS, Eichenfield LF. The epidemiology of molluscum contagiosum in children. J Am Acad Dermatol. 2006 Jan;54(1):47-54.
[5] Villa L, Varela JA, Otero L, Sánchez C, Junquera ML, Río JS, Vázquez F. Molluscum contagiosum: A 20-year study in a sexually transmitted infections unit. Sex Transm Dis. 2010 Jul;37(7):423-4.
[6] Olsen JR, Gallacher J, Piguet V, Francis NA. Epidemiology of molluscum contagiosum in children: a systematic review. Fam Pract. 2014 Apr;31(2):130-6.
[7] Koning S, Bruijnzeels MA, van Suijlekom-Smit LW, van der Wouden JC. Molluscum contagiosum in Dutch general practice. Br J Gen Pract. 1994 Sep;44(386):417-9.
[8] Pannell RS, Fleming DM, Cross KW. The incidence of molluscum contagiosum, scabies and lichen planus. Epidemiol Infect. 2005 Dec;133(6):985-91
[9] Forbat E, Al-Niaimi F, Ali FR. Molluscum Contagiosum: Review and Update on Management. Pediatr Dermatol. 2017 Sep;34(5):504-515.
[10] http://emedicine.medscape.com/article/910570; [Medscape]
[11] Reynolds MG, Holman RC, Yorita Christensen KL, Cheek JE, Damon IK. The Incidence of Molluscum contagiosum among American Indians and Alaska Natives. PLoS One. 2009;4(4):e5255.