Molluscum contagiosum virus commonly causes a localized chronic infection. Transmission is by direct contact; spread occurs by autoinoculation and via fomites (eg, towels, bath sponges) and bath water. Adults acquire the infection via close skin-to-skin contact with an infected person (eg, sexual contact, wrestling).
Patients with immunocompromise (eg, due to HIV/AIDS, corticosteroid use, or chemotherapy) may develop a more widespread infection (1 General references Molluscum contagiosum is characterized by clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter caused by molluscum contagiosum virus, a poxvirus... read more , 2 General references Molluscum contagiosum is characterized by clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter caused by molluscum contagiosum virus, a poxvirus... read more
).
Molluscum contagiosum is common among children.
General references
1. Meza-Romero R, Navarrete-Dechent C, Downey C: Molluscum contagiosum: An update and review of new perspectives in etiology, diagnosis, and treatment. Clin Cosmet Investig Dermatol 12:373–381, 2019. doi: 10.2147/CCID.S187224
2. Edwards S, Boffa MJ, Janier M, et al: 2020 European guideline on the management of genital molluscum contagiosum. J Eur Acad Dermatol Venereol 35(1):17–26, 2021. doi: 10.1111/jdv.16856
Symptoms and Signs of Molluscum Contagiosum
Molluscum contagiosum can appear anywhere on the skin except the palms and soles. Lesions consist of clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules, usually 2 to 5 mm in diameter, which occur most commonly on the face, trunk, and extremities in children and on the pubis, penis, or vulva in adults. Lesions may grow to 10 to 15 mm in diameter, especially among patients with HIV infection and other immunodeficiencies.
Lesions are usually not pruritic or painful and may be discovered only coincidentally during a physical examination. However, the lesions can become inflamed and itchy as the body fights off the virus.
Diagnosis of Molluscum Contagiosum
Clinical evaluation
Diagnosis of molluscum contagiosum is based on clinical appearance; skin biopsy or smear of expressed material shows characteristic inclusion bodies but is necessary only when diagnosis is uncertain.
Differential diagnosis includes folliculitis Diagnosis Folliculitis is an infection of hair follicles. Diagnosis is clinical. Treatment for most cases of bacterial folliculitis is with topical mupirocin or clindamycin. (See also Overview of Bacterial... read more , milia Cutaneous Cysts Epidermal inclusion cysts are the most common cutaneous cysts. Milia are small epidermal inclusion cysts. Pilar cysts are usually on the scalp and may be familial. Benign cutaneous cysts are... read more
, and warts Warts Warts are common, benign, epidermal lesions caused by human papillomavirus infection. They can appear anywhere on the body in a variety of morphologies. Diagnosis is by examination. Warts are... read more
(for lesions < 2 mm) and juvenile xanthogranuloma and Spitz nevus (for lesions > 2 mm).
Treatment of Molluscum Contagiosum
Physical removal: Curettage, cryosurgery, laser therapy, or electrocautery
Topical irritants (eg, trichloroacetic acid, cantharidin, tretinoin, tazarotene, podophyllotoxin [podofilox])
Sometimes intralesional injection or photodynamic therapy
Sometimes combination therapies
Most lesions spontaneously regress in 1 to 2 years, but they can remain for 2 to 3 years.
Treatment of molluscum contagiosum is indicated for cosmetic reasons or for prevention of spread. Options include curettage, cryosurgery, laser therapy, electrocautery, trichloroacetic acid (25 to 40% solution), cantharidin, podophyllotoxin (podofilox) in adults, tretinoin, and tazarotene. Some clinicians use salicylic acid, but others consider it too irritating for many body areas where molluscum occurs. Similar concerns exist with use of potassium hydroxide (KOH). Small studies suggest that ingenol mebutate gel, a cytotoxic agent used to treat actinic keratoses, may be effective (1 Treatment references Molluscum contagiosum is characterized by clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter caused by molluscum contagiosum virus, a poxvirus... read more ). Molluscum lesions within the orbital rim should be removed via gentle destruction by a skilled clinician. Lesions may be gently squeezed with a forceps to remove the central core. Treatments that cause minimal pain (eg, tretinoin, tazarotene, cantharidin) are used first, especially in children. Imiquimod is usually not recommended.
Curettage or liquid nitrogen can be used 40 to 60 minutes after application of a topical anesthetic such as EMLA (lidocaine/prilocaine) cream or 4% lidocaine cream under an occlusive dressing. EMLA cream must be applied judiciously because it can cause systemic toxicity, especially in children. In adults, curettage is very effective but painful if done without anesthetic.
Cantharidin is safe and effective but can cause blistering. It is applied in 1 small drop directly to the molluscum lesion. Areas that patients (especially children) may rub are covered with a bandage because contact with the fingers should be avoided. Cantharidin should not be applied to the face or near the eyes because blistering is unpredictable. If cantharidin comes into contact with the cornea, it can cause scarring. Cantharidin should be washed off with soap and water in 6 hours. Fewer than 15 lesions should be treated in one session because infection may occur after application of cantharidin. Parents should be warned about blistering if their children are prescribed this irritant.
Other treatments include intralesional injection (eg, with Candida antigen or occasionally interferon alpha; 2 Treatment references Molluscum contagiosum is characterized by clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter caused by molluscum contagiosum virus, a poxvirus... read more ) and photodynamic therapy. Antiviral and immunomodulatory medications have been more successful in patients infected with HIV (3 Treatment references Molluscum contagiosum is characterized by clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter caused by molluscum contagiosum virus, a poxvirus... read more
).
Dermatologists often use combination therapy such as liquid nitrogen or cantharidin in the office or a retinoid cream at home. This form of therapy is typically successful, but resolution often takes 1 to 2 months in some patients.
Children should not be excluded from school or day care. However, their lesions should be covered to reduce the risk of spread.
Treatment references
1. Shin K, Bae KN, Kim HS, et al: Ingenol mebutate gel for the treatment of molluscum contagiosum: An open-label comparative pilot study. J Am Acad Dermatol pii:S0190-9622(19)32689-1, 2019. doi: 10.1016/j.jaad.2019.08.081
2. Wells A, Saikaly SK, Schoch JJ: Intralesional immunotherapy for molluscum contagiosum: A review. Dermatol Ther 33(6):e14386, 2020. doi: 10.1111/dth.14386
3. Vora RV, Pilani AP, Kota RK: Extensive giant molluscum contagiosum in a HIV positive patient. J Clin Diagn Res 9(11):WD01-2, 2015. doi: 10.7860/JCDR/2015/15107.6797
Key Points
Molluscum contagiosum, caused by a poxvirus, commonly spreads by direct contact (eg, sexual contact, wrestling), fomites, and bath water.
Lesions tend to be asymptomatic clusters of 2- to 5-mm diameter papules that are pink, dome-shaped, smooth, waxy, or pearly and umbilicated.
Diagnose based on clinical appearance.
Treat for cosmetic reasons or prevention of spread.
Treatments can include destructive methods (eg, curettage, cryosurgery, laser therapy, electrocautery) or topical irritants (eg, trichloroacetic acid, cantharidin, tretinoin, tazarotene, podophyllotoxin).
Drugs Mentioned In This Article
Drug Name | Select Trade |
---|---|
cantharidin |
Ycanth |
tretinoin |
Altinac, Altreno, Atralin, AVITA, Refissa, Renova, Retin-A, Retin-A Micro, Tretin-X, Vesanoid |
trichloroacetic acid |
Tri-Chlor |
tazarotene |
ARAZLO, Avage, Fabior, TAZORAC |
podofilox |
Condylox |
salicylic acid |
Akurza , Aliclen, Bensal HP, Clear Away, Clear Away Liquid, Clear Away One Step, Clear Away Plantar, Clearasil Rapid Rescue Deep Treatment, Compound W, Compound W Total Care Wart & Skin, Corn/Callus Remover, Curad Mediplast, DermacinRx Atrix, DermacinRx Salicate, Dermarest Psoriasis Moisturizer, Dermarest Psoriasis Overnight Treatment, Dermarest Psoriasis Scalp Treatment, Dermarest Psoriasis Shampoo plus Conditioner, Dermarest Psoriasis Skin Treatment, Dr. Scholl's Callus Removers, Dr. Scholl's Corn Removers, Dr. Scholl's Extra Thick Callus Remover, Dr. Scholl's One Step Callus Remover, Dr. Scholl's One Step Corn Removers, Dr. Scholl's Ultra, Dr.Scholl's Dual Action FREEZE AWAY, Dr.Scholl's Duragel, DuoFilm Wart Remover, Freezone, Gold Bond Psoriasis Relief, Gordofilm , Hydrisalic, Ionil, Ionil Plus, Keralyt, Keralyt 5, Keralyt Scalp Complete, MOSCO Callus & Corn Remover, MOSCO One Step Corn Remover, Neutrogena Acne Wash, Neutrogena T/Sal Scalp, Occlusal-HP, P&S, RE SA , SalAC, Salactic Film , Salacyn, Salex, Salimez, Salimez Forte, Salisol , Salisol Forte , Salitech, Salitech Forte, Salitop , Salkera, Salvax, Scalpicin 2 in 1 Anti-Dandruff, Selsun Blue, Thera-Sal , Trans-Ver-Sal, UltraSal-ER, VIRASAL, Wart-Off, XALIX |
ingenol mebutate |
Picato |
imiquimod |
Aldara, Zyclara |
lidocaine/prilocaine |
ANODYNE LPT, Aprizio Pak II, DermacinRx Empricaine, DermacinRx Prizopak, Dolotranz, EMLA, Empricaine-II, Leva Set, Lido-Prilo Caine , Lidotor, LiProZonePak, LIVIXIL Pak, LP Lite Pak, Medolor Pak with Tegaderm Dressing, Microvix LP, Nuvakaan, Nuvakaan-II, Oraqix , PRILOHEAL PLUS 30, Prilovix, Prilovix Lite, Prilovix Lite Plus, Prilovix Plus, Prilovix Ultralite, Prilovix Ultralite Plus, Prilovixil, REAL HEAL-I, Relador, VallaDerm-90 |
lidocaine |
7T Lido, Akten , ALOCANE, ANASTIA, AneCream, Anestacon, Aspercreme with Lidocaine, Astero , BenGay, Blue Tube, Blue-Emu, CidalEaze, DermacinRx Lidogel, DermacinRx Lidorex, DERMALID, Ela-Max, GEN7T, Glydo, Gold Bond, LidaMantle, Lidocan, Lidocare, Lidoderm, LidoDose, LidoDose Pediatric, Lidofore, LidoHeal-90, LIDO-K , Lidomar , Lidomark, LidoReal-30, LidoRx, Lidosense 4 , Lidosense 5, Lidosol, Lidosol-50, LIDO-SORB, Lidotral, Lidovix L, LIDOZION, Lidozo, LMX 4, LMX 4 with Tegaderm, LMX 5, LTA, Lydexa, Moxicaine, Numbonex, ReadySharp Lidocaine, RectaSmoothe, RectiCare, Salonpas Lidocaine, Senatec, Solarcaine, SUN BURNT PLUS, Tranzarel, Xyliderm, Xylocaine, Xylocaine Dental, Xylocaine in Dextrose, Xylocaine MPF, Xylocaine Topical, Xylocaine Topical Jelly, Xylocaine Topical Solution, Xylocaine Viscous, Zilactin-L, Zingo, Zionodi, ZTlido |