Psoriasis is a chronic inflammatory disease affecting 1% to 3% of the world's population 1,2 and results from the interaction between genetics and environmental factors such as stress, infections, and drugs, causing a T-cell-mediated response. [1][2][3] Vaccination is an uncommon triggering factor for the flare-ups of several skin diseases, 2,4-6 and a potential association between vaccination and the onset or exacerbation of psoriasis has been previously documented. 2,[5][6][7] In this letter, we report four new cases of psoriasis flare-ups after an influenza vaccination (Table 1).The first patient was a 41-year-old man with chronic plaque psoriasis undergoing adalimumab therapy who developed a severe flare-up that required hospital admission 24 hours after an intramuscular Chiroflu influenza vaccination (Trivalent A/Victoria/2452/2019 H1N1, A/Hong Kong/2671/2019 H3N2, and B/Victoria/705/2018) (Figure 1). dGuttate Brodalumab

Background Many cutaneous manifestations have been described in possible association with the COVID-19 pandemic, including acral lesions resembling chilblains. The underlying pathomechanisms of COVID-19 chilblains are not fully understood. The aim of this study was to describe the clinical, pathological, and laboratory findings of a series of patients who developed chilblains during the COVID-19 outbreak and to investigate the possible factors that could be involved in the pathogenesis of these lesions. Methods We conducted a prospective cohort study that included 54 patients who presented with chilblains during the highest peak in the incidence of COVID-19 in Cantabria (northern Spain). Skin biopsies were performed on 10 of these patients who presented with recent lesions. Laboratory investigations, including immunological analysis, serological studies, and the assessment of cryoproteins, were also performed. Results Most patients presented erythematous plaques located on the toes and/or purpuric macules located on the feet. Histopathological findings were compatible with those of idiopathic chilblains. Immunohistochemical evaluation showed C3d and C4d deposits in the vessel walls in seven cases. The autoimmunity panel was negative in most of our series. Cryoprotein testing showed positive cryofibrinogen in two-thirds (66.7%) of the patients assessed. On follow-up, most patients presented almost complete resolution, although six patients required prednisone and antiaggregant drug treatment. Conclusions This study shows, for the first time to our knowledge, a high prevalence of cryofibrinogenemia in patients with chilblains during the COVID-19 pandemic. Cryofibrinogenemia could be implicated in the pathogenesis of chilblains related to COVID-19.

Calcinosis cutis (CC) is defined as the deposition of calcium salts on the skin and subcutaneous tissue. It is associated with different conditions, including some autoimmune diseases, and it can generate significant inflammation, pain, and functional impairment. Different therapies have been tried with limited results. Intralesional sodium thiosulfate seems a promising therapeutic option. We report a patient with diffuse systemic sclerosis who presented with two symmetrical plaques on both axillae, which caused pain and skin retraction. The clinical diagnosis was consistent with CC, which was confirmed by skin biopsy and ultrasound. The patient was treated with a 250 mg/ml solution of sodium thiosulfate injected into the plaques. Complete resolution was achieved after three monthly sessions. The only reported adverse effect was a transient burning sensation during the injections. Given its effectiveness and safety, we believe that intralesional sodium thiosulfate could become a valid first-line option for the treatment of CC.