Bissonnette 2014.

Methods	Randomised, parallel‐arm trial Five centres in Canada (community centre clinics) Period of inclusion: March 2010 to August 2011
Participants	Inclusion criteria Palmo‐Plantar Pustular Area and Severity Index (PPPASI) ≥ 8 on the hands and/or feet Palmo‐Plantar Physician Global Assessment (PPPGA) of moderate or severe Palmoplantar pustular psoriasis with at least 1 typical plaque of psoriasis outside the palms and soles or a history of a typical psoriatic plaque outside the palms and soles, the presence of pustules on palms or soles, or a palmoplantar disease morphology suggestive of psoriasis Palmoplantar pustulosis with no lesions suggestive of psoriasis anywhere on the skin and a palmoplantar disease morphology suggestive of PPP (pustules on palms or soles with or without erythema but without plaques suggestive of psoriasis) Age ≥ 18 years Exclusion criteria Not stated Baseline data: palmoplantar pustular psoriasis and palmoplantar pustulosis randomised 1:1 to ustekinumab 45 mg or 90 mg (based on weight) (15 participants) or placebo (18 participants). Total number of participants = 33 Mean age, years (± SD): 55.3 (± 6.75) for palmoplantar pustular psoriasis participants in the ustekinumab group; 50.50 (± 8.13) for palmoplantar pustular psoriasis participants in the placebo group; 49.8 (± 8.41) for palmoplantar pustulosis participants in the ustekinumab group; 52 (± 9.37) for palmoplantar pustulosis participants in the placebo group Male/female: 1/9; 2/8; 0/5; 3/5 Duration of condition: not stated PPPASI score (mean ± SD): 18.49 ± 9.06; 19.07 ± 5.71; 14.52 ± 4.13; 20.16 ± 10.19 Withdrawal: 1 patient in the ustekinumab group discontinued treatment because of side effects, as did 3 in the placebo group (1 because of side effects and 2 for withdrawal of consent)
Interventions	Intervention A: ustekinumab 45 mg or 90 mg (based on weight) (15 participants) Control intervention B: placebo (18 participants) Co‐interventions: none Duration of treatment: 16 weeks
Outcomes	Primary outcome Proportion who achieved 50% improvement in PPPASI (Palmo‐Plantar Pustular Area and Severity Index; PPPASI‐50) at week 16 for participants randomised to ustekinumab as compared to those randomised to placebo Secondary outcome Adverse events Quality of life base on Dermatology Life Quality Index (DLQI), Work Productivity and Activity Impairment questionnaire:Psoriasis (WPAI:PSO), and Palmoplantar Quality of Life Index (PPQoLI)
Notes	Research funded and medication provided by Janssen Inc. Canada. Funders were involved in study design but not in data collection, manuscript preparation, or publication decisions Clinical trial: NCT01091051
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Palmoplantar pustular psoriasis and palmoplantar pustulosis patients were randomised (1:1) to receive either ustekinumab or placebo. The sponsor generated the non‐blocked random allocation sequences for each cohort using Excel (Microsoft, Richmond, WA, USA) and provided them to sites in sequentially numbered envelopes" Comment: probably done
Allocation concealment (selection bias)	Low risk	Quote: "Palmoplantar pustular psoriasis and palmoplantar pustulosis patients were randomised (1:1) to receive either ustekinumab or placebo. The sponsor generated the non‐blocked random allocation sequences for each cohort using Excel (Microsoft, Richmond, WA, USA) and provided them to sites in sequentially numbered envelopes" Comment: probably done
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Patients were randomised to receive ustekinumab or placebo. Patients randomised to placebo received an equal volume injection of bacteriostatic sodium chloride at day 0 and week 4 followed by ustekinumab at weeks 16 and 20. The un‐blinded pharmacist who had access to the randomisation codes was the only person knowing the nature of the treatment dispensed to patients" Comment: participants were blind but the pharmacist was not
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "Patients were randomised to receive ustekinumab or placebo. Patients randomised to placebo received an equal volume injection of bacteriostatic sodium chloride at day 0 and week 4 followed by ustekinumab at weeks 16 and 20. The un‐blinded pharmacist who had access to the randomisation codes was the only person knowing the nature of the treatment dispensed to patients" Comment: the pharmacist was the only person knowing the nature of the treatment delivered
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: one participant in the ustekinumab group discontinued treatment because of side effects as did 3 in the placebo group (1 because of side effects and 2 for withdrawal of consent). All participants were included in the 'intention‐to‐treat' population and in the safety population
Selective reporting (reporting bias)	High risk	Comment: the study protocol is available but not all of the study’s pre‐specified secondary outcomes (PPPASI‐75 at week 16) have been reported in the pre‐specified way