#Molluscum contagiosum
– Treatment with Cantharidin (a topical blistering agent): Will use the blunt wooden end of a cotton swab to apply Cantharidin directly to the lesions without touching the surrounding skin. Will then cover the lesion with tape or a bandage to keep the vesicant from inadvertently spreading to the surrounding skin. Will keep the tape or bandage on for 2 to 6 hours or until the first sign of blistering. Will then remove the tape and wash the area with soap and water. The patient will RTC to repeat treatment every 2 to 4 weeks until all lesions have resolved. On average it takes about 2-3 applications to get complete clearance.
– Will treat only a few lesions at the first visit to see how the patient responds to cantharidin and will adjust the duration of the applications based on the initial response.
– Will avoid using cantharidin on the face, genital, or perianal areas.
– Side effects discussed include: 1) Blistering, burning, pain, erythema, and pruritus. Postinflammatory dyspigmentation may occur but typically resolves over several months. Scaring is uncommon but may occur. Patient/guardians understand the s/e and agree to the applications.
– Expected result: Should expect small blisters to form at the treatment site, followed by a disappearance of the molluscum lesion and healing without scarring.
– Treatment will be done by the clinician in the office. The patient would not be given cantharidin to apply at home.
Other first-line treatments of Molluscum Contagiosum
Cantharidin is a first-line treatment for molluscum contagiosum. Other first-line treatments for molluscum contagiosum are:
Cryotherapy
Tx: Will Dip the tip of a cotton swab (cotton bud) in liquid nitrogen and apply to each individual lesion for 6 to 10 seconds.
Side effects discussed: 1) Pain – adolescents and adults can tolerate the pain easily. Children may not tolerate the pain as easily and so may limit the use of cryotherapy to treat multiple lesions in kids.
2) Scarring and temporary or permanent hypopigmentation. Hypopigmentation may be prominent in people with dark skin.
Curettage
Tx: Use a curette to physically scrape off or remove the molluscum contagiosum lesion. An advantage is that the lesion is resolved immediately.
Side effects discussed: 1) Discomfort and minor bleeding. 2) There is a possibility of the developing small, depressed scars. Consider applying a topical anesthetic prior to curettage to reduce discomfort.
Electrocautery – see this video.
Podophyllotoxin (cream)
– Will use for lesions located on the thighs or genitalia.
– Apply 0.5% podophyllotoxin cream to lesion twice daily for three consecutive days per week for up to four weeks.
– Podophyllotoxin is an antimitotic agent that is commercially available as podofilox 0.5% (Condylox) in a solution, gel, or cream.
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“Molluscum contagiosum can be easily treated by curetting the lesions and inducing an inflammatory reaction. The lesions may disappear spontaneously in a few months; however, the best management of this condition in a patient who is bothered by it is to induce resolution.” ABFM
References:
https://www.ncbi.nlm.nih.gov/pubmed/20302243
Habif TP: Clinical Dermatology: A Color Guide to Diagnosis and Therapy, ed 6. Elsevier, 2016, pp 219-223.