Study	Reason for exclusion
Aso K 1983	Not an RCT
Carr 2008	Not an RCT
Cassano 2010	All included patients had palmoplantar psoriasis ‐ not palmoplantar pustulosis
Dupre 1973	Not an RCT
Duweb 2001	All cases concerned patients with palmoplantar psoriasis ‐ not palmoplantar pustulosis
Engin 2005	Only 4 of the included patients had palmoplantar pustulosis (and results are not specified clearly for them); the others had other types of palmoplantar dermatosis
Fritsch 1978	Not an RCT
Gjertsen 1980	Not an RCT
Grundmann‐Kollmann 1999	None of the selected patients had palmoplantar pustulosis
Gupta 2011	Not an RCT
Hofer 2006	Only 5 out of 8 participants had palmoplantar pustulosis and 3 had hyperkeratotic plaque psoriasis with no differentiation in results between the 2 subgroups
Janagond 2013	None of the selected patients had palmoplantar pustulosis
Khandpur 2011	All included patients had palmoplantar psoriasis, with no mention of the presence of pustulosis
Kumar 1997	All included patients had plaque‐type ‐ not pustular ‐ palmar and/or plantar psoriasis
Mehta 2011	All included patients had plaque‐type palmar and/or plantar psoriasis, and patients with palmoplantar pustulosis were excluded
Neumann 2006	None of the selected patients had palmoplantar pustulosis
Orfanos 1978	Trial includes different types of psoriasis
Papp 2012	All included patients had plaque psoriasis of palms, soles, and scalp, but not palmoplantar pustulosis
Rosen 1988	Study of epidermal Langerhans cells on skin biopsies
Schiener 2005	None of the selected patients had palmoplantar pustulosis
Sezer 2007	None of the selected patients had palmoplantar pustulosis (palmoplantar psoriasis ‐ no pustulosis described in inclusion criteria or patient description at baseline)
Thaci 2010	All patients had plaque‐type psoriasis, which may have involved palms or soles
Yaniv 2012	Not a randomised controlled trial
Zhang Jun 2007	Not an RCT

RCT: randomised controlled trial.