Wananukul 2012.

Methods	Split‐body randomised comparative trial. Duration: 2 weeks Assessment at days 0, 3–4, 6–7, and 14 Unit of randomisation: left or right half of body Unit of analysis: right/left side of body
Participants	Inclusion criteria: clinical diagnosis of ISD, bilaterally symmetrical distribution of lesions, any severity, and various body sites Exclusion criteria: any treatment within 2 weeks Number of participants randomised: 75 (mild 51, moderate 22, severe 2) Number of dropouts: 3, including 1 adverse event Sex: 50 boys, 25 girls Mean age: not reported; age range: 2–48 weeks Location: Thailand, not stated if inpatient or outpatient setting (paediatric department of hospital)
Interventions	Treatment (n = 75) Hydrocortisone 1% lotion Comparator (n = 75) Licochalcone 0.025% lotion in ceramide and linoleic acid lipid base formulation (Eucerin soothing lotion 12%) Applied twice daily for 14 days No details regarding instructions given to participants' parents/carers 3/75 did not complete the study
Outcomes	Primary outcome measure Severity score: composite score (range: 0–9) of clinical presentation of erythema, scales, and crusts, each evaluated on a score of 0–3 (0 = no lesion, 1 = mild, 2 = moderate, 3 = severe). Categorised as mild (cumulative score 1–3), moderate (4–6), and severe (7–9). Clearing rate at days 3–4, 6–7, and 14 and total number with complete clearance at end of study. Evaluated at days 0, 3–4, 6–7, and 14. Not stated who did the scoring. Secondary outcome measures Percentage of infants who develop adverse effects or intolerance to treatment Assessed by parent or clinician report (or both). No quality of life measures reported.
Notes	We assessed the risk of bias due to the split‐body design. We assessed the risk of cross‐contamination from the products being applied using an overlapping method particularly on the scalp as high risk. We assessed the risk of systemic absorption of the product affecting the lesions on the contralateral side as moderate. Funded by a research fund of the university. No conflicts of interest declared.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "block randomisation". Comment: did not fully describe method of randomisation.
Allocation concealment (selection bias)	Low risk	Quote: "sequentially numbered bottles from block randomisation before the study was started". Comment: allocation likely concealed.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "repacked in bottles which were identical". Comment: there was blinding of participants and personnel.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not explicitly stated who assessed the outcome
Incomplete outcome data (attrition bias) All outcomes	Low risk	3/75 did not complete the study.
Selective reporting (reporting bias)	Unclear risk	No study protocol.
Other bias	High risk	No apparent conflicts of interest or financial interests. High risk due to split‐body design, risk of cross‐contamination of the products affecting the other half of the scalp, and a theoretical risk of systemic absorption potentially affecting the contralateral body side.

IGA: Investigator's Global Assessment; n: number of participants; SD: standard deviation.