Murray 1980.

Methods	Within‐patient, controlled trial One centre in London Period of inclusion not stated
Participants	Inclusion criteria Bilaterally symmetrical palmoplantar pustulosis of at least 1 year's duration Exclusion criteria Not stated Participants were seen weekly by a single observer Baseline data Mean age, years: 47.8 for males and 52.9 for females Male/female: 6/16 Duration of disease, years: 5.3 Proportion of participants with psoriatic lesions elsewhere: not specified Withrawal: no dropouts
Interventions	Oral 8‐methoxypsoralen (8‐MOP) 2 hours before UVA irradiation (4 times per week) for 30 treatments administered to all 22 participants Intervention 1 UVA irradiation (22 palms or soles, or both) Intervention 2 Other side was covered (22 palms or soles, or both) Duration of treatment: 30 treatments (sessions) (7.5 weeks)
Outcomes	No primary or secondary outcome pre‐specified Response using a visual analogue scale (VAS) score Total dose used
Notes	Funding: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Patients were irradiated four times per week on one randomly selected side" Comment: insufficient information about the sequence generation process to permit judgement
Allocation concealment (selection bias)	Unclear risk	Comment: no information on method to guarantee allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote: "The opposite side was covered and served as a control" Comment: as 1 side was covered, blinding was impossible
Blinding of outcome assessment (detection bias) All outcomes	High risk	Comment: no mention of blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quote: "The treated side cleared completely in twelve patients, almost cleared in five patients and improved in four. One patient improved on both sides" Comment: no missing outcome data
Selective reporting (reporting bias)	Unclear risk	Comment: no protocol found to guarantee that all planned outcomes are presented in the results