Egyptian physicians found certain plants to be effective in the treatment of vitiligo (a skin condition resulting from loss of pigment which produces white patches). Today, modern researchers have harnessed these same plant chemicals to help treat psoriasis. The chemicals, known as “psoralens,” are found in buttercups, figs, limes, and parsnips. When activated by ultraviolet (UV) lamps, the healing compounds are unlocked.

Greek physician Hippocrates writes about conditions affecting the “derm.”

Joseph Jacob Plenck first writes of desquamative (scaly or scale-like) diseases.

Robert Willan was the first to recognize psoriasis as an independent disease, which he referred to as “Willan's lepra.”

Viennese dermatologist Ferdinand Hebra first ascribed the name “psoriasis” from the Greek word meaning “to itch.”

Balmanno Squire mistakenly stumbles upon the treatment of psoriasis using Goa powder containing anthralin (dithranol), which is used in treatments today.

Dr. William Goeckerman develops the “Goeckerman regimen,” combining coal tar and UV light.

John Ingram develops the "Ingram regimen," combining coal tar, UVB light, and anthralin (derived from Squire's Goa powder discovery 75 years earlier).

Topical corticosteroids (steroids) are applied to affected areas, then wrapped under occlusive dressings. 

The first systemic treatment, methotrexate, is approved by the FDA for treating psoriasis.

Cyclosporine, which works by suppressing the immune system, was first found to be effective in the treatment of psoriasis while treating organ transplant patients who also had psoriasis. With this discovery, researchers first realized that psoriasis might be a disorder of the immune system.

Extensive research performed to develop biologic medications that act on the immune system and slow the rapid production of skin cells that causes a psoriasis flare-up.