European consensus-based interdisciplinary guideline for diagnosis, treatment and prevention of actinic keratoses, epithelial UV-induced dysplasia and field cancerization on behalf of European Association of Dermato-Oncology, European Dermatology Forum, European Academy of Dermatology and Venereology and Union of Medical Specialists (Union Européenne des Médecins Spécialistes).

A collaboration of multidisciplinary experts from the European Association of Dermato-Oncology, the European Dermatology Forum, the European Academy of Dermatology and Venereology, and the European Union of Medical Specialists was formed to develop European recommendations on AK diagnosis and treatment, based on current literature and expert consensus. This guideline addresses the epidemiology, diagnostics, risk stratification and treatments in immunocompetent as well as immunosuppressed patients. Actinic keratoses (AK) are potential precursors of cutaneous squamous cell carcinoma (cSCC) and display typical histopathologic and immunohistochemical features of this malignancy in an early stage. They can develop into cSSC in situ and become invasive in a low percentage of cases. AK is the most frequent neoplasia in white populations, frequently occurring within a cancerous field induced by ultraviolet radiation. Since it cannot be predicted, which lesion will progress to cSCC and when treatment is usually recommended. The diagnosis of AK and field cancerization is made by clinical examination. Dermatoscopy, confocal microscopy, optical coherence tomography or line-field confocal-OCT can help in the differential diagnosis of AK and other skin neoplasms. A biopsy is indicated in clinically and/or dermatoscopically suspicious and/or treatment-refractory lesions. The choice of treatment depends on patients' and lesion characteristics. For single non-hyperkeratotic lesions, the treatment can be started upon patient's request with destructive treatments or topical treatments. For multiple lesions, field cancerization treatment is advised with topical treatments and photodynamic therapy. Preventive measures such as sun protection, self-examination and repeated field cancerization treatments of previously affected skin areas in high-risk patients are advised.

he Influence of Academician Franjo Kogoj on Global Dermatology.

Academician Franjo Kogoj graduated medicine in 1920 in Prague, where he then pursued training in dermatovenerology. During later years, he also visited other dermatology clinics in Europe, where he collaborated with renowned dermatologists of the time, such as in Breslau (present day Wroclaw in Poland) with Josef Jadassohn and in Strasbourg with Lucien-Marie Pautrier. He was also active in the famous Saint-Louis hospital in Paris. Academician Kogoj's scientific interests were especially focused on allergies, exanthemas, skin tuberculosis, and keratodermas. Kogoj was very active in defining a precise and useful terminology for various dermatological conditions, where the terminology was in many ways confusing and often overlapping, such as in cases of eczema and dermatitis. Kogoj performed experimental studies of allergic reactions in eczema and atopic dermatitis and introduced the term pruridermatitis (Pruridermatitis allergica chronica) into dermatological terminology instead of the name neurodermitis and other synonyms essentially describing atopic dermatitis (endogenous eczema, prurigo-asthma, prurigo Besnier). Academician Kogoj managed to define Mal de Meleda as a separate form of hereditary keratoderma and was engaged in the clinical symptomatology, serology, and therapy of syphilis, whereby he emphasized the so-called "critical moment" in the treatment of syphilis. Academician Kogoj's most famous scientific achievement was his histological definition of the spongiform pustule in the pathomorphology of psoriasis, which became a groundbreaking histological novelty in the classification of psoriasis, thus bearing Kogoj's name in the medical literature to this date. Academician Kogoj published many scientific and professional articles, books, monographs and contributions to manuals and textbooks. He was honored nationally as well as internationally as a leading expert in the field of medicine and dermatology, receiving many eminent awards and recognitions throughout his scientific career.