Patchy baldness that typically begins with rapid hair loss on discrete areas of the scalp and sometimes progresses to complete baldness and even loss of body hair. The characteristic diagnostic finding is short, broken hairs called ‘exclamation point’ hairs. Alopecia areata affects both males and females and, most often, children and young adults. It seems to be caused by an autoimmune mechanism, wherein the body’s own immune system attacks the hair follicles and disrupts normal hair formation. Alopecia areata is sometimes associated with allergic disorders, thyroid disease, vitiligo, lupus, rheumatoid arthritis, ulcerative colitis, and other conditions, and some forms may be inherited. Hair can sometimes regrow within a year without treatment. The longer the period of time of hair loss, the less chance that the hair will regrow.
- Alopecia capitis totalis
Alopecia capitis totalis: Loss of all scalp hair, with normal hair elsewhere on the body remaining.
- Alopecia, traumatic
Alopecia, traumatic: Hair loss caused by injury to the scalp. Common causes include the use of caustic hair straighteners, especially those that include lye as an ingredient; stress traction injury from tight rollers and braiding; overheating of the hair shafts; and compulsive pulling out of hair (trichotillomania).
- Alpha blocker
Alpha blocker: A drug that blocks receptors in arteries and smooth muscle. This action relaxes the blood vessels and leads to an increase in blood flow and a lower pressure for the control of hypertension. The action in the urinary tract enhances urinary flow in prostatic hypertrophy (enlarged prostate). The alpha blockers include doxazosin (Cardura), […]
- Alpers disease
Alpers disease: A progressive disease of the nervous system characterized by spasticity (tightness), myoclonus and dementia and by liver problems with jaundice and cirrhosis. This disorder, first described by Alpers in 1931 as “Diffuse progressive degeneration of gray matter of cerebrum”, usually begins early in life with convulsions. A continuous seizure (status epilepticus) is often […]
- Alpha cell, pancreatic
Alpha cell, pancreatic: A type of cell found in areas within the pancreas called the islets of Langerhans. Alpha cells make and release glucagon, which raises the level of glucose (sugar) in the blood.