Hydra vulgaris, a tiny boneless freshwater creature distantly related to the sea anemone, has an impressive ability to regenerate itself. Cutting a hydra in half will create two even smaller hydras, a phenomenon called morphallaxis.
As we discussed psoriasis vulgaris in lecture, the dermatologist was quick to point out that we should, in good conscience, not name the condition as such to a patient. “Call it ’plaque-like psoriasis.’ The second part of the name ’vulgaris’ can frighten patients and instil stigma about their condition.
He was right. It was hard to separate the term from the vivid imagination of the mind. Even though I had already seen pictures of the condition, the word association was stuck. How often had we described offensive material or things in poor taste as vulgar?
However, it was not always like that. Vulgaris is from the Latin word vulgus, meaning ”the common people.“ In middle English, it had many ordinary uses. But eventually, it was used by the aristocracy to describe the common people in a negative light: a lack of sophistication or good taste, an unrefined understanding, an offensive, coarse, or rude reference.
And thus, it continues to exist in our vocabulary, as a twisted version of the original. But these original medical terms remain: Psoriasis vulgaris. Acne vulgaris. Pemphigus vulgaris. All use vulgaris as a modifier, to reflect the fact that the condition they describe is the ”common“ form of the disease. Nothing more.