Psoriasis is defined as chronic, immune-mediated disease. Regardless of the development of new therapeutic approaches, the precise etiology of psoriasis remains unknown and speculative. The aim of this review was to systematize the results of previous research on the role of oxidative stress and aberrant immune response in the pathogenesis of psoriasis, as well as the impact of certain therapeutic modalities on the oxidative status in patients with psoriasis. Complex immune pathways of both the innate and adaptive immune systems appear to be major pathomechanisms in the development of psoriasis. Oxidative stress represents another important contributor to the pathophysiology of disease, and the redox imbalance in psoriasis has been reported in skin cells and, systemically, in plasma and blood cells, and more recently, also in saliva. Current immune model of psoriasis begins with activation of immune system in susceptible person by some environmental factor and loss of immune tolerance to psoriasis autoantigens. Increased production of IL-17 appears to be the most prominent role in psoriasis pathogenesis, while IL-23 is recognized as master regulator in psoriasis having a specific role in cross bridging the production of IL-17 by innate and acquired immunity. Other proinflammatory cytokines, including IFN-γ, TNF-α, IL-1β, IL-6, IL-22, IL-26, IL-29, or IL-36, have also been reported to play important roles in the development of psoriasis. Oxidative stress can promote inflammation through several signaling pathways. The most noticeable and most powerful antioxidative effects exert various biologics compared to more convenient therapeutic modalities, such as methotrexate or phototherapy. The complex interaction of redox, immune, and inflammatory signaling pathways should be focused on further researches tackling the pathophysiology of psoriasis, while antioxidative supplementation could be the solution in some refractory cases of the disease.

Background. Acute hemorrhagic edema of infancy (AHEI) is a rare vasculitis, which presents dramatically as palpable purpuric skin lesions on the limb, face and auricles, with swelling of these parts and low-grade fever, in children up to 2 years of age. To date, approximately 400 cases have been described in the literature. The etiology remains mostly unknown. With or without treatment, AHEI goes to spontaneous recovery within 1-3 weeks, usually without any complications. To our knowledge, compartment syndrome as complication of AHEI has only been reported in one case. We present an unusual case of AHEI with serious complications due to compartment syndrome of the right-hand fingers. Case. A 16-month-old male child presented with fever and sudden appearance and rapid spread of palpable, painless, non-itching ecchymotic hematomas on the thigh, cheeks, earlobes, forearms, dorsum of hands and feet, with mild edema of these regions. Complete systemic examination and all vital parameters were normal for age. There was no history of bleeding disorders in the family. Except low hemoglobin on complete blood count and increased D-dimer values, all other laboratory investigations were in the normal range. Changes on the right forearm and hand expanded on almost the entire dorsal side and all surfaces of the fingers, with pronounced swelling and formation of bullous lesions, which were spreading and cracking. Skin biopsy confirmed nonspecific small-vessel vasculitis. That required the use of Methylprednisolone, low-molecularweight heparin, antibiotics and debridement of necrotic eschar, with necrectomy of the affected fingers. Conclusions. Early recognition of AHEI is important to avoid unnecessary investigation and therapy. On the other hand, our reported case warns that unexpected complications may occur.

Acute hemorrhagic edema of infancy (AHEI) is a rare vasculitis of small dermal vessels with characteristic presentation in infants aged up to 24 months. It manifests as a sudden occurrence of palpable purpuric skin lesions, swellings in hands, feet, face and auricles, and mild fever. The children affected with AHEI are almost always in good general health and with normal laboratory parameters. Approximately 400 cases have been described in the literature so far. However, the etiology is still unknown. Most evidence suggests infections or vaccination as the principal triggers. Extra cutaneous manifestations are recorded in only about 10% of AHEI patients. The majority of the affected children undergoes recovery spontaneously and without any complications within 1-3 weeks, with or without any treatment. AHEI is usually diagnosed on the clinical grounds only and the diagnostic procedure rarely requires a skin biopsy. The current literature indicates the use of corticosteroids and/or antihistamines as a therapy, but there is still a lot of controversy about these therapeutic measures. This paper presents the case of AHEI with its typical clinical manifestations that resolved in a rapid spontaneous recovery without the use of any treatment within a week. AHEI is a rare syndrome that pediatricians should be well familiar with in order to differentiate it from other potentially severe diseases that have similar cutaneous manifestations, but also to avoid unnecessary investigations and therapy.