Report Evaluation of ICAM-1 expression and vascular changes in the skin of patients with plaque, pustular, and erythrodermic psoriasis Aline L. Bressan 1 , MSc, Bruna L. S. Picciani 2 , PhD , Luna Azulay-Abulafia 1 , PhD, Anna K. Fausto-Silva 2 , PhD, Paula N. Almeida 2 , PhD, Karin S. G. Cunha 2 , PhD, Eliane P. Dias 2 , PhD, and Sueli Carneiro 1,3 , PhD 1 Sector of Dermatology, Rio de Janeiro State University, Rio de Janeiro, Brazil, 2 Graduate Program in Pathology, School of Medicine, Fluminense Federal University, Rio de Janeiro, Brazil, and 3 Sector of Dermatology, Medical Clinic Department, Rio de Janeiro Federal University, Rio de Janeiro, Brazil Correspondence Bruna L. S. Picciani, PHD Department of Pathology School of Medicine University Hospital Federal Fluminense University Marqu^ es de Parana, 303, 4° floor 24033-900, Rio de Janeiro Brazil E-mail: brunapicciani@gmail.com Funding: None. Conflicts of interest: None. Abstract Background Psoriasis is a chronic inflammatory disease. Pustular, erythrodermic, and extensive plaque psoriasis are responsible for systemic complications. Systemic capillary leak syndrome is the complication with greater progression to death and occurs due to vascular changes. Purpose The aim of this study was to evaluate vascular changes through the expression of CD34 and ICAM-1 in plaque, pustular, and erythrodermic psoriasis. Methods The sample consisted of seven patients with erythrodermic psoriasis, 24 with moderate-severe plaque psoriasis, 14 with mild plaque psoriasis and 13 with pustular psoriasis. Patients were submitted to physical examination and skin biopsy for histopathological examination and immunohistochemical analysis with anti-CD34 and anti- ICAM-1 antibodies. Subsequently, tissue fragments were organized by groups using the Tissue Macroarray (TMA) technique to perform immunohistochemistry. Results In 58 patients, analysis of vessels using anti-CD34 demonstrated vascular immunostaining in superficial dermis and between dermal papillae. There were more blood vessels in erythrodermic psoriasis, followed by plaque psoriasis. In erythrodermic psoriasis, there were small and few tortuous blood vessels with great dilatation, while plaque psoriasis presented larger vessels that were less dilated and more tortuous. There was an intense and localized expression of ICAM-1 in endothelial and lymphocytic cells in all groups, with significant differences. Conclusions Vascular alterations are important in psoriasis, with an increase in the number of blood vessels and ICAM-1 overexpression, especially in erythrodermic form. Therefore, vascular changes and the expression of intercellular adhesion molecules could help to diagnose the erythrodermic form of psoriasis. Introduction Psoriasis is a chronic immune-mediated inflammatory disease characterized by desquamative erythematous lesions. There is no predilection for sex, and it can occur at any age. 1 Its devel- opment depends on predisposing genetic factors, triggering external stimuli, and also changes in the immune system, with activation of T lymphocytes. 1 These cells stimulate the release of proinflammatory cytokines, especially tumor necrosis factor alpha (TNF-alpha). 2 Psoriasis can manifest in various forms (plaque, guttate, inverted, pustular, arthropathic, and erythroder- mic psoriasis) and can be severe. Severe psoriasis occurs in 20–30% of patients and, among these, 10–15% have associ- ated psoriatic arthritis. 2 Psoriasis is considered extensive when more than 10% of the body surface area (BSA) is affected. 3 Approximately 350 people die annually from psoriasis or from treatment compli- cations. 3 Systemic capillary leak syndrome is the complication with greater progression to death and most often arises from pustular and erythrodermic forms of psoriasis. 1,4,5 The leak syndrome is rare and is caused by increased capillary perme- ability, which results in accumulation of fluid and proteins in the interstitial or extravascular space, with subsequent hypov- olemic shock. 6,7 ª 2018 The International Society of Dermatology International Journal of Dermatology 2018, 57, 209–216 209