Acanthosis nigricans


Acanthosis nigricans
Acanthosis nigricans
Classification and external resources

Acanthosis nigricans on axilla
ICD-10 L83
ICD-9 701.2
OMIM 100600
DiseasesDB 58
MedlinePlus 000852
eMedicine derm/1
MeSH D000052

Acanthosis nigricans is a brown to black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds,[1] such as the posterior and lateral folds of the neck, the axilla, groin, umbilicus, forehead, and other areas.

Contents

Causes

It typically occurs in individuals younger than age 40, may be genetically inherited, and is associated with obesity or endocrinopathies, such as hypothyroidism or hyperthyroidism, acromegaly, polycystic ovary disease, insulin-resistant diabetes, or Cushing's disease.

Endocrine

The most common cause of acanthosis nigricans is insulin resistance, which leads to increased circulating insulin levels. Insulin spillover into the skin results in its abnormal increase in growth (hyperplasia of the skin). The condition most commonly associated with insulin resistance is type 2 diabetes mellitus, but is also a prominent feature of obesity, polycystic ovary syndrome, Donohue syndrome, and Rabson-Mendenhall syndrome. Acanthosis nigricans may also be seen with certain medications that lead to elevated insulin levels (e.g., glucocorticoids, niacin, insulin, oral contraceptives, and protease inhibitors).[2]

Malignant

In the context of a malignant disease, acanthosis nigricans is a paraneoplastic syndrome and is then commonly referred to as acanthosis nigricans maligna. Involvement of mucous membranes is rare and suggests a coexisting malignant condition.[3]

When seen in individuals older than age 40, this disorder is commonly associated with an internal malignancy, usually adenocarcinoma, and most commonly of the GI tract or uterus; less commonly of the lung, prostate, breast, or ovary. The stomach is the most common site.[4] Acanthosis nigricans of the oral mucosa or tongue is highly suggestive of a neoplasm, especially of the GI tract.

Other

Other causes of acanthosis nigricans are familial, drug-induced and idiopathic.

Types

Classification of Acanthosis nigricans according to Schwartz, 1994 [5] [6]

  • Benign acanthosis nigricans
  • Acanthosis nigricans associated with obesity
  • Syndromic acanthosis nigricans
  • Malignant acanthosis nigricans
  • Acral acanthosis nigricans
  • Unilateral acanthosis nigricans
  • Drug-induced acanthosis nigricans
  • Mixed acanthosis nigricans

Other Classifications of Acanthosis nigricans

Acanthosis nigricans may also be divided into the following types[7]:506:

  • Acral Acanthotic Anomaly (Acral Acanthosis Nigricans)
  • Acanthosis nigricans type I
  • Acanthosis nigricans type II
  • Acanthosis nigricans type III

Signs, tests, and misdiagnoses

Physicians can usually diagnose acanthosis nigricans by simply looking at a patient's skin. A skin biopsy may be needed in unusual cases. If no clear cause of acanthosis nigricans is obvious, it may be necessary to search for one. Blood tests, an endoscopy, or x-rays may be required to eliminate the possibility of diabetes or cancer as the cause.

Additionally acanthosis nigricans has similar visual characteristics (neck discoloration) with Casal collar, which is a symptom of pellegra (a nutrient deficiency disease, easily remedied with supplementation). In early stages of discoloration, it is hard for a non trained eye to distinguish one from the other.

Treatment

People with acanthosis nigricans should be screened for diabetes and, although rare, cancer. Controlling blood glucose levels through exercise and diet often improves symptoms. Acanthosis nigricans maligna may resolve if the causative tumor is successfully removed.[8]

Prognosis

Acanthosis nigricans often fades if the underlying cause can be determined and treated appropriately.

External links

References

  1. ^ "acanthosis nigricans" at Dorland's Medical Dictionary
  2. ^ Higgins SP, Freemark M, Prose NS (2008). "Acanthosis nigricans: a practical approach to evaluation and management.". Dermatol Online J 14 (9): 2. PMID 19061584. 
  3. ^ Schnopp C, Baumstark J (2007). "Oral acanthosis nigricans". N Engl J Med 357 (9): e10. doi:10.1056/NEJMicm062917. PMID 17761587. 
  4. ^ Rigel DS, Jacobs MI (1980). "Malignant acanthosis nigricans:a review". J Dermatol Surg Oncol 6 (11): 923. PMID 6257767. 
  5. ^ Garofalo, L.; A.M. Biscozzi, V. Mastrandrea, E. Bonifazi (2003). "Acanthosis nigricans vulgaris. A marker of hyperinsulinemia.". Eur. J. Pediat. Dermatol. 13: 85–8. http://www.dermatologiapediatrica.com/volume13/acanthosis.pdf. Retrieved 2010-07-29. 
  6. ^ Schwartz, Robert A. (1994). "Acanthosis nigricans". Journal of the American Academy of dermatology 31 (1): 1–19. doi:10.1016/S0190-9622(94)70128-8. PMID 8021347. 
  7. ^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0.
  8. ^ Brown J, Winkelmann RK (1968). "Acanthosis nigricans: study of 90 cases". Medicine 47 (1): 33. PMID 4868603. 

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Look at other dictionaries:

  • Acanthosis Nigricans — L acanthosis nigricans est une maladie de la peau faite de taches épaissies et bronzées. L origine étymologique de ce nom est à la fois grecque et latine : du grec akantha qui signifie épine, écaille et du latin nigricare qui signifie être… …   Wikipédia en Français

  • acanthosis nigricans — acanthosis ni·gri·cans nig rə .kanz, nī grə n a skin disease characterized by gray black warty patches usu. situated in the axilla or groin or on elbows or knees and sometimes associated with cancer of abdominal viscera * * * diffuse velvety… …   Medical dictionary

  • Acanthosis nigricans —   [zu Acanthus und lateinisch nigricare »schwärzlich sein«] die, , Hautkrankheit (Akanthose) …   Universal-Lexikon

  • Acanthosis nigricans — L acanthosis nigricans est une maladie de la peau faite de taches épaissies et bronzées. L origine étymologique de ce nom est à la fois grecque et latine : du grec akantha qui signifie épine, écaille et du latin nigricare qui signifie être… …   Wikipédia en Français

  • Acanthosis nigricans — Klassifikation nach ICD 10 L83 Acanthosis nigricans Q82.8 Sonstige näher bezeichnete angeborene Fehlbildungen der Haut …   Deutsch Wikipedia

  • acanthosis nigricans — noun a skin disease characterized by dark wartlike patches in the body folds; can be benign or malignant • Syn: ↑keratosis nigricans • Hypernyms: ↑skin disease, ↑disease of the skin, ↑skin disorder * * * ˈnigrə̇ˌkanz, ˈnīg noun …   Useful english dictionary

  • acanthosis nigricans — (лат. nigrico иметь темную окраску) дерматоз, характеризующийся ворсинчатыми и бородавчатыми ороговевающими разрастаниями аспидно черного цвета, симметрично расположенными в области шеи, подмышечных впадин, наружных половых органов, промежности,… …   Большой медицинский словарь

  • acanthosis NIGRICANS BENIGNA — (лат. benignus доброкачественный) А. п., наблюдающийся у молодых людей, страдающих эндокринными нарушениями или заболеваниями нервной системы …   Большой медицинский словарь

  • acanthosis NIGRICANS MALIGNA — (лат. malignus злокачественный) А. п., сопутствующий онкологическим заболеваниям внутренних органов …   Большой медицинский словарь

  • Nigricans — Nigricans, a Latin word meaning black, may refer to : Acanthosis nigricans, a brown to black, poorly defined, velvety hyperpigmentation of the skin Species and subspecies Species Latin binomial name abbreviations A. nigricans… …   Wikipedia


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