Grattan 1991.

Methods	Within‐participant, randomised controlled trial The study was probably conducted in a secondary care setting at a single centre in the UK
Participants	15 participants with vesicular hand eczema for at least 6 months Dropouts: 3 Inclusion criteria of the trial 16 years of age or older Recurrent disabling symmetrical vesicular hand eczema for at least 6 months with periods of remission (complete clearance) not exceeding 1 month in the previous 6 Exclusion criteria of the trial Pustular psoriasis Chronic hyperkeratotic dermatitis Chronic fungal infection Relevant allergy Predominantly irritant dermatitis Pregnancy Phototoxicity Use of immunosuppressive drugs Study population Gender: 3 female, 9 male Age: mean 49.7 years, SEM 4.1 years, range 24 to 69 years
Interventions	Intervention • Topical PUVA 3 times a week for 8 weeks on 12/15 hands Control intervention • UVA (with placebo psoralen paint) on 12/15 contralateral hands Moisturisers were allowed on both hands, and both hands received a small fraction of UVB from UVA lamps During an unclear follow‐up period, participants received a questionnaire Duration 8 weeks
Outcomes	Primary outcomes of the trial Not defined Other outcomes Observer‐rated global rating on a 5‐point scale (0 = clear, 1 = minimal, 2 = mild, 3 = moderate, 4 = severe) at a weekly interval Participant‐rated VAS to indicate improvement at weeks 0, 4, 8, 12, and 16 Observer‐rated severity score: T‐120 scores: multiplying surface area involved with severity scores (0 to 4) for vesiculation, erythema and scaling in weeks 0, 4, 8, 12, and 16 Questionnaire after completion of the study Adverse events
Notes	Small number of participants. The secondary outcomes ‐ reduction in severity, investigator‐rated and participant‐rated, and time until relapse ‐ were included but did not provide reproducible data. Exact figures for main outcomes are not given; instead there are graphic presentations. Questionnaire assessment was performed after completion of the study, but duration of follow‐up in this questionnaire assessment remains unclear Declarations of interest: not stated Funding: not stated Sample size rationale: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "psoralen and placebo were randomised and coded by one independent investigator (GJS) and supplied in bottles labelled left and right" Comment: no further details
Allocation concealment (selection bias)	Low risk	Quote: "psoralen and placebo were randomised and coded by one independent investigator (GJS) and supplied in bottles labelled left and right" Comment: randomisation and coding were accomplished by an independent investigator, and bottles were supplied labelled 'left' and 'right'; therefore the physician was unaware of allocation
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "psoralen and placebo were randomised and coded by one independent investigator (GJS) and supplied in bottles labelled left and right" Quote: "the placebo was...." Comment: double‐blind study with a similar looking placebo; it was not possible for the participant to distinguish these
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "the code was not broken until completion of the study" Comment: double‐blind design in which an independent investigator supplied the treatments. It was not possible for observers to know the treatment groups
Incomplete outcome data (attrition bias) All outcomes	Low risk	No intention‐to‐treat analysis but per protocol (12 of 15 = 80%)
Selective reporting (reporting bias)	Unclear risk	No trial register found. No major differences between outcomes described in the Methods section and outcomes described in the Results section; however although the article text claims that separate scores for the T‐120 are described, we were unable to find a score for separate items
Other bias	Low risk	Baseline comparisons: as within‐participant study not applicable Diagnostic certainty: yes The study was completed