Dictionary > Hypertrichosis

Hypertrichosis

Definition
noun, plural: hypertrichoses
An atypical hair growth in excess over the body
Supplement
Trichosis is an archaic term defined as a disease or abnormality characterized by an overgrowth of hair. The term hypertrichosis is the more widespread medical term used to refer to a condition characterized by an atypical growth of too much hair over the body. Hypertrichosis may be localized, i.e. the hair growth over a certain body part, and thus, is called localized hypertrichosis. An example is synophrys, which is a hypertrichosis in between the eyebrows. This condition gives an appearance of a single long eyebrow (or unibrow). When hypertrichosis involves the entire body the condition is referred to as generalized hypertrichosis, as in the case of werewolf syndrome (or terminal hypertrichosis).
Hypertrichosis may be congenital or later acquired in life. Congenital hypertrichosis is caused by genetic mutations. Examples of congenital hypertrichosis are as follows:

  • congenital hypertrichosis lanuginosa (a condition wherein the lanugo hair remains after birth and may not be replaced by vellus hair even at adulthood)
  • terminal hypertrichosis (a condition wherein the entire body is covered with fully pigmented terminal hair)
  • circumscribed hypertrichosis (a condition marked by the presence of thick vellus hair on upper extremities, e.g. hairy elbow syndrome)
  • nevoid hypertrichosis (congenital but may also occur later in life, a condition characterized by excessive terminal hair growing over an isolated body area)

Acquired hypertrichosis results from taking certain drugs or is associated with cancer. Examples include acquired hypertrichosis lanuginosa (characterized by lanugo hair growth especially on the face), acquired patterned hypertrichosis, and acquired localized hypertrichosis.
Word origin: hyper– (over) + trichosis, from Greek thrix (hair) –osis (condition)
See also:


You will also like...

Psychiatry and mental disorders
Psychiatry & Mental Disorders

Different mental disorders are described here. Read this tutorial to get an overview of schizophrenia, affective mood di..

An artistic depiction of a human embryo
Growth and Development of a Human Baby

Upon fertilization, a zygote forms and develops into an embryo. This tutorial elaborates on the growth and development f..

Plant meristem
Plant Meristems and Growth

In plants, growth occurs in meristems, which are the site of repeated cell division of unspecialized cells. These cells ..

Photosynthesis and respiration
Plant Metabolism

Plants are responsible for incredible feats of molecular transformation. Plant processes, such as photosynthesis, photop..

Geological Periods
Geological Periods

Geological periods is a study guide that cites the different geological periods on Earth's timeline. Each has a brief ov..

Homeostatic Mechanisms and Cellular Communication
Homeostatic Mechanisms and Cellular Communication

Homeostasis is the relatively stable conditions of the internal environment that result from compensatory regulatory res..