Summary of study features.

Table 1: Summary of study features.

Author and Year	Study Design	Participants	Intervention	Outcome
Cazzaniga, et al. [11]	Within- patient randomized clinical trial	17 patients, male and female, aged 18-65, with plantar pustulosis lesions and a diagnosis of chronic palmoplantar pustulosis, present for > 1 year, involving > 5% of the plantar surface area, symmetrically distributed, with a difference of expansion between right and left sides < 10%. Exclusion criteria: Plantar hyperkeratosis lesions, patients who had received systemic therapy for psoriasis, or UV therapy in the 3 months prior to study.	Patients were randomized to receive on one foot a sock made of fluorine- synthetic fiber, and on the other foot a sock made of cotton, for 4 weeks.	The median lesion reduction at week 4 was 42.6% in fluorine-synthetic arm, and 2.7% reduction in cotton arm (p = 0.148). The overall reduction over time in the treated areas was significantly in favor of fluorine- synthetic arm (p = 0.045) as well as the overall change in perception of the disease by the patient (p = 0.025). Patient satisfaction did not differ between treatment arms (p = 0.074).
Cazzaniga, et al. [12]	Double- blind, within- patient randomized clinical trial	20 patients, male and female, aged 18-65, with plantar psoriatic hyperkeratosis lesions present for > 1 year, involving > 5% of the plantar surface area, symmetrically distributed, with a difference in extension between the right and left sides < 10%. Exclusion criteria: Pustule lesions, patients who had received systemic therapy for psoriasis or UV therapy in the 3 months prior to study.	Patients were randomized to receive on one foot a sock made of fluorine- synthetic fiber, and on the other foot a sock made of cotton, for 4 weeks.	The median lesion reduction was 11.95% in fluorine-synthetic fiber arm and 11.89% in cotton arm (p = 0.776). Patient satisfaction was in favor of the fluorine-synthetic fiber arm (p = 0.011).
Collyer [13]	Narrative review and author perspective	Patients with psoriatic arthritis.	Discussion on custom and “off-the-shelf” footwear interventions with features designed to address pathology specific to various arthritidies.	The authors recommend that ready-made footwear interventions be lightweight, incorporate depth to accommodate swelling, a cushioning insole, and avoid hard toe-cap and stitching which can lead to irritation.
Corn, et al. [14]	Case Study	A 46-year-old female patient with pre-existing psoriasis, who developed psoriatic lesions on the plantar surfaces of her feet after beginning to play tennis. It was concluded that these lesions followed the normal weight-bearing distribution of the foot.	A foot orthoses designed to diminish the normal vertical and shear force during ambulation.	Use of this foot orthoses led to successful resolution of the psoriatic plantar foot lesions.
Loughrey, et al. [15]	Narrative review and author perspective	Patients with musculoskeletal rheumatologic diseases, including psoriatic arthritis.	Discussion on multi-disciplinary management strategies for pain related to rheumatologic disease, including foot orthoses.	Provision of foot orthoses in the early stages of inflammatory disease aims to prevent foot deformity and stabilize the foot. The use of simple, accommodative, and functional foot orthoses in the management of deformity and altered foot mechanics has been shown to reduce foot pain, disability, and functional limitation.
Maxwell [16]	Case Study	A 47-year-old male patient with chronic polyarticular psoriatic arthritis, namely impacting his ankles. Several therapeutic modalities had been prescribed, including NSAIDs, corticosteroids, and methotrexate.	Foot orthotics were prescribed, in combination with exercises, stretching, and analgesia.	The patient experienced improvement in ankle and foot-related symptoms after initiation of the foot orthoses, which included the use of a heel lift to address achilles tendinopathy, a medial arch support to stabilize the subtalar joint, a soft poron top layer to provide cushioning, and a metatarsal bar to protect the first MTP joint.
Farber, et al. [17]	Narrative review and author perspective	Patients with palmoplantar psoriasis.	Discussion on specific sock and footwear characteristics.	Psoriasis may be improved with tight-fitting shoes which reduce friction as much as possible, to thereby reduce the Koebner phenomenon. Additionally, shoes should minimize hyperhidrosis as much as possible. Socks are recommended to be worn at night time following the application of topical treatment to the feet.