A Brief History of Psoriasis Management in Canada.

Psoriasis is a chronic, inflammatory disease with a varying degree of clinical presentations. Managing psoriasis has always been arduous due to its chronicity and its propensity to relapse. Prior to the development of targeted biologic therapies, there were few effective treatments for psoriasis. Ancient psoriasis therapies included pinetar, plant extracts, psychotherapy, arsenic, and ammoniated mercury. In the 19th century, chrysarobin was developed. Then, in the early half of the 20th century, anthralin and coal tar were in widespread use. In the latter half of the 20th century, treatments were limited to topical first-line therapies, systemic drugs, and phototherapy. However, as the treatment of psoriasis has undergone a revolutionary change with the development of novel biologic therapies, patients with moderate to severe psoriasis have been able to avail therapies with high efficacy and durability along with an acceptable safety profile. This article is a brief historical review of the management of psoriasis prior to the inception of biologics and with the development of novel biologic therapies.

Blue gods, blue oil, and blue people.

Studies of the composition of coal tar, which began in Prussia in 1834, profoundly affected the economies of Germany, Great Britain, India, and the rest of the world, as well as medicine and surgery. Such effects include the collapse of the profits of the British indigo monopoly, the growth in economic power of Germany based on coal tar chemistry, and an economic crisis in India that led to more humane tax laws and, ultimately, the independence of India and the end of the British Empire. Additional consequences were the development of antiseptic surgery and the synthesis of a wide variety of useful drugs that have eradicated infections and alleviated pain. Many of these drugs, particularly the commonly used analgesics, sulfonamides, sulfones, and local anesthetics, are derivatives of aniline, originally called "blue oil" or "kyanol." Some of these aniline derivatives, however, have also caused aplastic anemia, agranulocytosis, and methemoglobinemia (that is, "blue people"). Exposure to aniline drugs, particularly when two or three aniline drugs are taken concurrently, seems to be the commonest cause of methemoglobinemia today.