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.