Butterfly rash: A red, flat facial rash over the bridge of the nose. Many patients with systemic lupus erythematosus (SLE) develop this characteristic rash. Because of its shape, it is frequently referred to as the “butterfly rash” of lupus.
The butterfly rash of lupus is typically painless and does not itch. Along with inflammation in other organs, the butterfly rash of lupus can be precipitated or worsened by exposure to sunlight, a condition called photosensitivity. The photosensitivity can be accompanied by a worsening of inflammation throughout the body, causing a “flare” of the disease.
A “butterfly” rash can also occur in other conditions such as rosacea and seborrheic dermatitis.
- Butyric acid
Butyric acid: An acid that has four carbons in it. The formula for butyric acid is: CH3-CH2-CH2-COOH.
Bx: Abbreviation for biopsy, the removal of a sample of tissue for examination or other study. Biopsies are most frequently studied by use of a microscope to check for possible abnormalities such as inflammation or cancer. A biopsy may also be used for specialized purposes such as to start cell cultures to analyze a genetic […]
Bypass: An operation in which a new pathway is created for the transport of substances in the body.
- Bypass, cardiopulmonary
Bypass, cardiopulmonary: A bypass of the heart and lungs as, for example, in open heart surgery. In this procedure, blood returning to the heart is diverted through a heart-lung machine (a pump-oxygenator) before being returned to the arterial circulation.
BSL-1: Biosafety level 1. The lowest level of biosafety, a level that applies to agents that do not ordinarily cause human disease.