Psoriasis (PsO) is a chronic skin disease. This study aims to evaluate clinical and subclinical response to calcipotriol+betamethasone foam, in patients with PsO, comparing, for the first time, data from microvascular ultrasound (MicroV) and shear wave elastography (SWE) with Psoriasis Area and Severity Index (PASI).

Methods Between November 2018 and April 2019 in Tor Vergata Hospital (Roma, Italy), we enrolled 26 patients with PsO who were ageds 20–75 years, with PASI score ≥4, candidated for calcipotriol+betamethasone foam treatment. They underwent MicroV and SWE evaluation at baseline (T₀) and after 4 weeks of treatment (T₄). Clinical follow-up was carried on at T₄, T₈ and T₁₂. Student’s t-test (p values<0.05 statistically significant) was used to compare SWE and PASI values.

Results At T₀, SWE stiffness values of target plaques (61.5% on elbows, 23% knees, 7.7% sacrum,7.7% legs) were significantly higher than values under healthy skin. At T₄, all patients showed a significant reduction of PASI; MicroV showed reduction in vascularisation of responsive plaques in 85% of cases, only in 15%, the vascularisation degree remained stable; and SWE values of target plaques were significantly lower compared with T₀. Only in 7.7%, there was a relapse at T₁₂.

Conclusions Calcipotriol+betamethasone foam is a very effective topical treatment in a short-medium term follow-up in patients with PsO. MicroV and SWE evaluate response to treatment (in term of plaque vascularisation and stiffness), so they could represent promising early indicators of therapeutic response and help the physician to establish a better clinical-therapeutic management of patients with PsO.