Sjövall 1987.

Methods	Parallel‐group, randomised controlled trial (3 groups) This study was carried out in a secondary care setting and was probably a single‐centre study in Sweden
Participants	18 participants (3 male, 15 female) with chronic hand eczema of different types resistant to conventional therapy (11 patch test‐proven relevant allergy, 4 atopic, 3 endogenous) Dropouts: 3 Inclusion criteria of the trial Chronic hand eczema Resistant to conventional topical treatment with potent corticosteroids and moisturisers Exclusion criteria of the trial Not defined Study population Gender: 15 female, 3 male Age: mean 45 years, range 26 to 67 years
Interventions	Intervention • UVB irradiation only on hands 4 times a week for 8 weeks in 6 participants • Filtered light (placebo UVB, no UVB) on the hands 4 times a week for 8 weeks in 6 participants • Hand UVB followed by whole‐body UVB + UVA 4 times a week during 8 weeks in 6 participants Their 'ordinary topical treatment' was permitted in all groups Three months after end of treatment, participants were mailed a questionnaire regarding the course of their hand eczema and their opinions on treatment Duration 8 weeks with an email follow‐up after 3 months
Outcomes	Primary outcomes of the trial Not defined Other outcomes Observer‐rated severity scoring system (0 = unchanged/worse, 1 = improved, 2 = cleared) after 4 weeks (16 exposures), if a participant cleared before the end of the study, or at 8 weeks (end of treatment after 32 exposures) Participant‐rated follow‐up questionnaire 3 months after end of treatment, regarding the course of hand dermatitis and the burden of treatment (time consuming) Adverse events
Notes	Small number of participants. Main table unclear: results at 8 weeks or at 20 weeks? Follow‐up at 3 months presented in a descriptive way, without exact details Declarations of interest: not stated Funding: the study was supported by grants from Alfred Österlund and Finsen Foundations Sample size rationale: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "the patients were randomly divided..." Comment: no further details
Allocation concealment (selection bias)	Unclear risk	No details about how allocation was concealed from participants and clinicians
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "the whole device was covered by green clothes, thus making it possible to perform a double blind trial between the patients in group 1 and 2" Comment: the investigators covered the machine with green clothes; by this method, 2 groups (A and B) were blinded; however the third group of participants was not blinded because they received whole‐body irradiation. Staff probably was not blinded
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	The investigators state a partly double‐blind design; however it is unclear how observers were blinded, and if they were independent observers
Incomplete outcome data (attrition bias) All outcomes	Low risk	No intention‐to‐treat analysis but per protocol (15 of 18 = more than 80%)
Selective reporting (reporting bias)	Low risk	No trial registration found. No major differences between Materials and Methods sections
Other bias	Unclear risk	Baseline comparisons: no baseline comparisons Diagnostic certainty: yes The study was completed