2. Responses of contacted authors.

Author	Requested information	Contacted	Reply
Dr. Luigi Naldi	“Randomized, within‐patient, clinical trial comparing fluorine‐synthetic fiber socks with standard cotton socks in improving plantar pustulosis”, published in Dermatology in 2014, vol 228, N°2 Outcome: proportion of participants cleared or almost cleared, preferably measured as an objective measure of disease severity Outcome: proportion of participants with adverse effects serious or severe enough to have caused withdrawal of participants from the study	1 October 2017	None of the treated sides cleared in the included patients
Pr. Diamant Thaci	“A phase IIIb, multicentre, randomised, double‐blind, vehicle‐controlled study of the efficacy and safety of adalimumab with and without calcipotriol ⁄betamethasone topical treatment in patients with moderate to severe psoriasis: the BELIEVE study”, published in British Journal of Dermatology in 2010, vol 62 Info requested: Did the included patients have palmoplantar plaque psoriasis, palmoplantar pustular psoriasis, or a combination of both?	1 October 2017	All included patients had plaque‐type psoriasis; thus the study was excluded
Dr. Bissonnette	“Etanercept in the treatment of palmoplantar pustulosis”, published in Journal of Drugs in Dermatology in 2008, vol 7, N°10 Outcome: proportion of participants cleared or almost cleared, preferably measured as an objective measure of disease severity Outcome: proportion of participants with adverse effects serious or severe enough to have caused withdrawal of participants from the study “Increased expression of IL‐17A and limited involvement of IL‐23 in patients with palmo‐plantar (PP) pustular psoriasis or PP pustulosis; results from a randomised controlled trial”, published in Journal of the European Academy of Dermatology and Venereology in 2013, vol 28, N°10 Outcome: proportion of participants cleared or almost cleared, preferably measured as an objective measure of disease severity Outcome: proportion of participants with adverse effects serious or severe enough to have caused withdrawal of participants from the study	1 October 2017 11 October 2017	One patient (treated with etanercept) achieved PPPASI > 75% No serious or severe adverse effects that caused withdrawal from the study
Dr. Reich	“Oral alitretinoin treatment in patients with palmoplantar pustulosis inadequately responding to standard topical treatment: a randomised phase II study”, published in British Journal of Dermatology in 2016, vol 174 Outcome: proportion of participants cleared or almost cleared, preferably measured as an objective measure of disease severity Outcome: proportion of participants with adverse effects serious or severe enough to have caused withdrawal of participants from the study	1 October 2017 11 October 2017 25 October 2017	No reply
Dr Wilson	“APRICOT ‐ Anakinra for pustular psoriasis”, Trial Nb: ISRCTN13127147 Info requested: status of the study and the results, mainly the proportion of participants cleared or almost cleared, preferably measured as an objective measure of disease severity as well as the proportion of participants with adverse effects serious or severe enough to have caused withdrawal of participants from the study	1 October 2017 11 October 2017 25 October 2017	The trial is still in progress at the moment, so study authors had no results to share
Dr. Petzelbauer	"Comparison of fumaric acid ester‐PUVA versus PUVA‐etretinate in palmoplantar pustolosis," unpublished study EudraCT 2006‐004519‐23, registered in 2009 (EudraCT Number: 2006‐004519‐23. Sponsor Protocol Number: 08/08) Info requested: any unpublished results	12 June 2018	No reply