| Methods |
Randomised controlled trial |
| Participants |
32 children, 5 to 10 years of age, recruited in local paediatricians' offices, university clinics and through mass emails to university students and staff, North Carolina, USA |
| Interventions |
Cantharidin collodion 0.7% versus vehicle collodion for approximately 8 weeks |
| Outcomes |
Complete clearance, lesion counts, adverse effects, approximately 8 weeks after start of treatment |
| Notes |
Funding: Doris Duke Charitable Foundation |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
"Randomization schedule was prepared before first recruitment using permuted blocks of size 2" |
| Allocation concealment (selection bias) |
Low risk |
After eligibility was assessed, study personnel "assigned the next unique subject identification number and dispensed the appropriate drug" |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
"Patients, parents and investigators were blinded to treatment assignment" and "placebo was identical in texture and smell" |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
"Patients, parents and investigators were blinded to treatment assignment" and "placebo was identical in texture and smell" |
| Incomplete outcome data (attrition bias)
Short‐term outcomes (up to 3 months) |
Low risk |
2 participants dropped out immediately after randomisation because they did not meet all eligibility criteria (< 20%). |
| Incomplete outcome data (attrition bias)
Medium‐ and long‐term outcomes (3‐6 months and longer) |
Unclear risk |
No long‐term data |
| Selective reporting (reporting bias) |
Low risk |
Reported outcomes similar to those in trial register resume. |
| Other bias |
Unclear risk |
Imbalance in dry skin. Allocation bias was due to dropout. |
