HX17 Niels Ryberg Finsen, the ‘Light Doctor’

Abstract Niels Ryberg Finsen was a pioneer in the field of dermatology. Known in Denmark as the ‘Light Doctor’, he revolutionized phototherapy, which has now become a cornerstone of modern dermatology. Born in the Faroe Islands in 1860, he studied medicine in the University of Copenhagen. Around this time, he began to have a metabolic condition, causing weakness and fatigue. Now thought to have had Niemann–Pick disease, Finsen discovered that exposure to light made him feel more energized. A keen researcher, Finsen devoted his time to studying the benefits of light therapy on medical conditions. He founded the Finsen Institute in 1896, which became a global leader in light therapy research for skin disorders. He was awarded the Nobel Prize in Physiology or Medicine in 1903, for his pioneering work relating to light therapy in the treatment of skin tuberculosis (lupus vulgaris). This is one of the first Nobel Prizes awarded in medicine, and one among the few awarded relating directly to the field of dermatology. He discovered that ultraviolet (UV) and red light could have therapeutic benefits to skin infections caused by Mycobacterium tuberculosis, which was a significant public health concern at the time. Over the next century, this discovery laid the groundwork for further advancements in light therapy, paving the way for modern dermatological treatments such as narrowband UVB therapy for psoriasis, eczema, vitiligo and other autoimmune skin conditions, as well as photodynamic therapy and blue light therapy for skin cancer and acne. Moreover, the laser therapies widely used in the treatment of acne, pigmentation disorders and wound healing are further extensions of the core principles discovered by Finsen, and proof of his lasting influence on modern medicine. Sadly, Finsen’s own metabolic condition progressed. His disease prevented him from attending the Nobel Prize ceremony, and he died shortly after at the age of 44 years. The lifetime work of Niels Ryberg Finsen has inspired countless scientists and dermatologists alike, and led to medical advancements with a lasting impact that continues to be felt in dermatology today.