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$Unique_ID{BRK03409}
$Pretitle{}
$Title{Acanthosis Nigricans}
$Subject{Acanthosis Nigricans Keratosis Nigricans Miescher's Syndrome, also
known as Benign Acanthosis Nigricans or Benign Keratosis Nigricans
Pseudoacanthosis Nigricans Gougerot-Carteaud Syndrome, also known as Confluent
Reticular Papillomatosis Malignant Acanthosis or Keratosis Nigricans}
$Volume{}
$Log{}
Copyright (C) 1986, 1989, 1990 National Organization for Rare Disorders,
Inc.
115:
Acanthosis Nigricans
** IMPORTANT **
It is possible that the main title of the article (Acanthosis Nigricans)
is not the name you expected. Please check the SYNONYM listing to find the
alternate names and disorder subdivisions covered by this article.
Synonyms
Keratosis Nigricans
DISORDER SUBDIVISIONS:
Miescher's Syndrome, also known as Benign Acanthosis Nigricans or Benign
Keratosis Nigricans
Pseudoacanthosis Nigricans
Gougerot-Carteaud Syndrome, also known as Confluent Reticular
Papillomatosis
Malignant Acanthosis or Keratosis Nigricans
General Discussion
** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only. It should not be used for diagnostic or treatment
purposes. If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section.
Acanthosis nigricans is a dermatological disorder characterized by grey
or black darkening and thickening of the skin. It is often associated with
cancer or obesity, but benign hereditary forms also exist.
Symptoms
Small blackish and thickened patches result from excessive accumulation of
melanin in the basal layer of the skin in Acanthosis Nigricans. Small warts,
freckles, dry areas, and other small malformations occur on and between the
lesions, which may become velvety in texture. Without treatment, the lesions
tend to progress, except in the hereditary form, where they may become more
numerous during adolescence, only to regress after puberty. The skin may
become hairless, and the fingernails may deteriorate.
Lesions usually occur symmetrically in such areas as the underarms, neck,
face, backs of hands, forearms, between the breasts, groin, inner thighs,
genitals, buttocks, around the anus, and sometimes the mucous membranes of
the mouth, anus, etc.
Acanthosis nigricans occurs in four forms including:
1. An inherited benign form known as Miescher's syndrome
2. A form prevalent in young adult females called
Gougerot-Carteaud syndrome, which may also be hereditary
3. A form associated with obesity or endocrine disorders,
called pseudo-acanthosis nigricans
4. An adult form almost always associated with visceral cancer.
In all but the adult form, the lesions eventually stop multiplying and
regress. In adult forms related to cancer, the lesions' progress,
paralleling that of the underlying malignancy.
Causes
The causes of Acanthosis Nigricans seem to vary, and are poorly understood.
Miescher's syndrome appears to be inherited by an autosomal dominant
mechanism. (Human traits including the classic genetic diseases, are the
product of the interaction of two genes for that condition, one received from
the father and one from the mother. In dominant disorders, a single copy of
the disease gene (received from either the mother or father) will be
expressed "dominating" the normal gene and resulting in appearance of the
disease. The risk of transmitting the disorder from affected parent to
offspring is 50% for each pregnancy regardless of the sex of the resulting
child.)
Pseudoacanthosis nigricans occurs with such endocrine disorders as
pituitary adenoma, Addison's disease, diabetes mellitus, and disorders of the
ovaries such as Stein-Leventhal syndrome. It is also seen in cases of
obesity. The adult form usually coexists with carcinomas of the stomach or
various abdominal organs. Occasionally, it occurs with breast or lung
cancers.
Therapies: Standard
Lesions associated with obesity usually regress as weight is lost and any
thyroid imbalances are corrected. Similarly, Acanthosis Nigricans associated
with cancer regresses with remission or cure of the underlying disease.
Therapies: Investigational
This disease entry is based upon medical information available through
January 1990. Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.
Resources
For more information on Acanthosis Nigricans, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
The National Arthritis and Musculoskeletal and Skin Diseases Information
Clearinghouse
Box AMS
Bethesda, MD 20892
(301) 495-4484
For information on genetics and genetic counseling referrals, please
contact:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
(914) 428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
MENDELIAN INHERITANCE IN MAN, 8th ed.: Victor A. McKusick; Johns Hopkins
University Press, 1986. P. 4.
CECIL TEXTBOOK OF MEDICINE, 18th ed.: James B. Wyngaarden, and Lloyd H.
Smith, Jr., Eds.: W. B. Saunders Co., 1988. P. 1112.