Kaaber 1983.

Methods	Randomised controlled, parallel‐group design This study was probably conducted in a secondary care setting at 2 Danish departments of dermatology
Participants	30 female participants with pompholyx more than 6 months, and positive patch test to nickel Dropouts: 6 Inclusion criteria of the trial Pompholyx of the hands of more than 6 months' duration At least 1 flare every 2 weeks A positive patch test to nickel Exclusion criteria of the trial Not defined Study population Gender: 30 female, no male Age: median 25 years, range 19 to 67 years
Interventions	Intervention • Oral tetraethylthiuram disulphide (TETDS) 50 mg/d first week, increasing to 200 mg/d for at least 6 weeks in 11/15 participants for at least 6 weeks Control intervention • Placebo tablets in 13/15 The total duration of the study was probably 8 weeks (?); however run‐in time and total duration of treatment are not completely clear Both groups were allowed to use desoximetasone ointment and emollients Duration Probably 8 weeksIS
Outcomes	Primary outcomes of the trial Not defined Other outcomes Participant‐rated (?) number of flares at each 2‐ to 3‐week visit Observer‐rated score of severity: area involved 0 to 4, erythema 0 to 3, number of vesicles 0 to 3, scaling 0 to 3 Number of participants healed (not specified in Methods) Amount of corticosteroid ointment used since last visit Adverse events
Notes	Study duration unclear. Timing of outcome assessments not clear. Comparison based on slopes of linear regression of scores. The secondary outcomes ‐ reduction in severity, investigator‐rated, and dose reduction ‐ were included but did not provide reproducible data Declarations of interest: not stated Funding: Hoechst Danmark and Dumex Ltd. Danmark supplied the study drugs Sample size rationale: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "referring to a system of random numbers, the patients received..." Comment: reference to a system of random numbers
Allocation concealment (selection bias)	Unclear risk	Unclear if this concerned an open list and unclear how allocation was concealed
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "the tablets were identical in appearance" Comment: study authors stated double‐blinded design; this is considered an adequate way to blind participants
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Double‐blind design. No information is given about how observer blinding was achieved
Incomplete outcome data (attrition bias) All outcomes	Low risk	No intention‐to‐treat analysis but per protocol (24 of 30 = 80%)
Selective reporting (reporting bias)	Unclear risk	No trial registration found. For observer‐rated severity score, the Results section states only that this was not statistically significant, only with regards to scaling and the frequency of flares. The Results section is very concise
Other bias	Unclear risk	Baseline comparisons: not stated Diagnostic certainty: yes The study was completed