Erlichman 1981.

Methods	Double‐blind, randomised, placebo‐controlled, parallel‐group trial. No intention‐to‐treat analysis.
Participants	Inclusion criteria Infants with seborrhoeic dermatitis, onset before 3 months of age Involvement of the flexures, skin creases including behind the ears, but not the cheeks No pruritis Spontaneous disappearance by age 8 months (retrospective criteria, see notes below). Exclusion criteria: if rash persisted to 8 months, diagnosis changed to infantile eczema and that participant retrospectively excluded from study. Number of participants randomised: total 20, outcome reported for 16 (7 in treatment group and 9 in comparator group) Number of dropouts: 1 lost to follow‐up, 3 excluded as diagnosis revised to infantile eczema when rash persisted to 8 months Sex: not reported Location: Jerusalem, paediatric department No topical therapy given during the trial. Age range: not reported; mean age (months): 2.1 (SD 1.3) in biotin group and 2.6 (SD 1.1) in placebo group Total 20 infants included
Interventions	Treatment (n = 10) Oral biotin 5 mg given daily for 2 weeks. Comparator (n = 10) Placebo (oral glucose) given daily for 2 weeks. Clinical outcomes reported for n = 7 in biotin group and n = 9 in placebo group.
Outcomes	Primary outcome measures Age at disappearance of rash Total duration of illness Duration of illness after entry into trial Adverse effects not reported. No quality of life outcomes reported. Outcomes assessed 2 weekly until resolution of rash or 8 months of age.
Notes	Biotin supplied freely by pharmaceutical laboratory, funding from Michael and Adelaide Kennedy‐Leigh Foundation.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	High risk	1/20 participants lost to follow‐up. 3/20 participants excluded from analysis on basis of outcome, but outcome separately reported (i.e. non‐resolution of rash at age 8 months).
Selective reporting (reporting bias)	Unclear risk	No study protocol.
Other bias	Unclear risk	Insufficient information given in Methods section. Biotin supplied by pharmaceutical company.