The downy hair on the body of the fetus and newborn baby.
The lanugal hair (or lanugo) is the first hair to be produced by the fetal hair follicles. It is very fine, soft and usually is unpigmented.
The lanugal hair is prenatal hair. It appears at about 5 months of gestation and begins to be shed at 7 and 8 months of gestation.
The postnatal hair that succeeds the lanugal hair is conventionally divided into vellus and terminal hair. The vellus resembles the lanugal hair in that it is short, soft and usually unpigmented. The terminal hair is longer, coarser and usually pigmented. There are intermediate types of hair. Any given follicle can change the type of hair it is making.
“Lanugo” is the Latin word for down, like the fine small hairs of plants.
- Hair-on-end skull
Thin fine linear extensions radiating out from the skull that look on an X-ray like hair standing “on-end” from the skull, an appearance associated with hemolytic anemias such as sickle cell disease and thalassemia. The “hair” represents the accentuated trabeculae extending between the inner and outer skull tables through the diploe in the expanded bone […]
A wad of swallowed hair. Hairballs sometimes cause blockage of the digestive system, especially at the exit of the stomach. Also called ‘trichobezoar.
- Hairy cell leukemia
A rare type of chronic leukemia in which the abnormal white blood cells appear to be covered with tiny hairs when examined microscopically. The hairy cells are malignant B lymphocytes. There may be too few normal blood cells of all types because of an exc
An unpleasant odor from the mouth, commonly referred to as bad breath. Halitosis can be caused by the consumption of certain foods, poor oral hygiene, alcohol or tobacco use, dry mouth, or by certain chronic medical conditions.
- Hallervorden-Spatz disease
A genetic disorder in which there is progressive neurologic degeneration with the accumulation of iron in the brain. The gene for the disease is on chromosome 20 in region 20p13-p12.3. The syndrome was first described by Julius Hallervorden and Hugo Spatz in 1922 in 5 sisters who showed increasing dysarthria (trouble speaking) and progressive dementia […]