Cantharidin is cited in the dermatology and pediatric literature as a valuable treatment option. Treatment is often available in private practice offices, where a prescribing physician may offer a non-FDA approved treatment on an individualized basis. The situation is different in many hospital and academic settings, such as our own for example, where the formulary is defined through a FDA-approved indication. The absence of an indication precludes its addition to many hospital formularies, thus limiting the options available to a prescribing physician and denying patient access to a treatment offered in the private practice setting. An indication and formulary status require controlled clinical trials on the safety and efficacy of cantharidin in MC. The objective of this trial is to see if this commercially-viable cantharidin formulation has a comparable safety and efficacy profile as formulations previously studied under conditions which most closely match the what has been historically done in the clinic.

Inclusion Criteria:

Diagnosis of MC by the Principal Investigator.

Maximum of 50 lesions on locations including the face, trunk, back, left or right arm, left or right leg, hands, feet, buttocks, and groin.

Execution of Informed Consent and or assent forms

Exclusion Criteria:

Patients with immunosuppression, including organ transplantation, HIV infection.

Patients utilizing immunosuppressive agents (including oral corticosteroids) will be excluded except for patients using inhaled corticosteroids, such as those utilized for asthma or allergic rhinitis.

Females who have reached menarche and are sexually active as well as pregnant patients will be excluded as the effects of this drug have not been evaluated in pregnancy.

Patients who have greater than 50 MC lesions will also be excluded from the study.

Adverse event data was collected through study completion, up to 12 weeks.