In general, patients show an area of darkening and thickening of skin without any symptoms. Occasionally, pruritus may be seen. The lesions often start as hyperpigmented macules and patches and progress into plaques that are palpable [6] [7].

In one out of three average cases of malignant acanthosis nigricans, the patients show skin changes before the signs of cancer become visible. In another one out of three of cases, the lesions of the acanthosis nigricans arise at the same time as the neoplasm. In other cases, the skin findings only become visible after cancer has been diagnosed. Cases of abrupt and exuberant appearance of acanthosis nigricans are common and they are associated with a higher rate of pruritus.

The onset of the disorder can be traced to medication or supplement usage.

• Candidiasis

  Maltez et al. reported a case of AIDS who presented with three opportunistic infections (esophageal candidiasis, tuberculosis and atypical mycobacteriosis) with acanthosis nigricans. [ijdvl.com]

  Differential Diagnosis (Other conditions with similar appearance) Atopic Dermatitis Becker nevus Candidiasis Erythrasma Giant melanocytic nevi Hypertrophic seborrheic keratosis Linear epidermal nevus Pemphigus vegetans Diagnosis Key Points *Diagnosis [ozarkderm.com]

  Histopathological examination of skin showed features of AN with fungal hyphae and spores suggestive of cutaneous candidiasis (Figure 4). Abdominal ultrasonography showed altered hepatic echogenicity, splenomegaly, and bilateral enlarged kidneys. [journalssc.com]

  […] insulin sensitivity.[31] Cosmetic treatments that have been tried include using alexandrite laser, dermabrasion, and chemical peels.[32] Surgical removal is the main treatment for malignant lesions.[33] Differential Diagnosis Seborrhea Tinea Erythrasma Candidiasis [ncbi.nlm.nih.gov]

• Congestive Heart Failure

  Cardiac abnormalities of the condition include hypertrophic cardiomyopathy, hypertension, cardiomegaly, congestive heart failure and ventricular dysfunction. Our patient showed no evidence of cardiac involvement. [journalssc.com]

  Obesity has been cited as “a risk factor for CVD, ventricular dysfunction, congestive heart failure, stroke, and cardiac arrhythmias” [15]. [oatext.com]

• Yawning

  By Richard Klasco, M.D Photo Credit Ask Well Photo Credit Why Do We Yawn? Reading about yawning makes people yawn. You are probably yawning right now. By Roni Caryn Rabin Latest Search Latest Articles Search Articles 13843 results for sorted by [nytimes.com]

• Hypertension

  Whereas 7% of white students were classified as pre-hypertensive/hypertensive, the rate for Hmong students was 17%. [ncbi.nlm.nih.gov]

  The distribution of risk factors were diabetes 2 (0.5%), hypertension 2 (0.5%), obesity 13 (3.3%), family history of diabetes 170 (42.5%), family history of hypertension 96 (24%) and family history of both diabetes and hypertension 57 (14.2%). [journals.lww.com]

  Obesity (89.09%) was the most common associated condition followed by dyslipidemia (87.2%), metabolic syndrome (56%), hypertension (38.18%), diabetes (18.8%) and hypothyroidism (14.54%). [nepjol.info]

  The relationship of AN with hypertension may not be as strong as that with fatty liver and abnormal glucose homeostasis. [hkmj.org]

• Heart Disease

  Environmental and Occupational Health Eye Care Family / Intimate Partner Violence General Health Health Disparities Collaboratives Heart Disease Heat Illness Hepatitis HIV Hypertension Immunizations Infectious Disease Influenza & The Avian Flu Lead Men's [migrantclinician.org]

  Metabolic syndrome with and without C-reactive protein as a predictor of coronary heart disease and diabetes in the West of Scotland Coronary Prevention Study. Circulation 2003;108:414-9. PubMed 70. [escholarship.org]

  Interestingly people of mixed ancestry were identified in that study to exhibit low risk for both diabetes and its associated complication, ischaemic heart disease [3]. [dmsjournal.biomedcentral.com]

  […] risk for all of the components of the metabolic syndrome: obesity, hypertension, elevated triglycerides, low high-density lipoprotein, and glucose intolerance. [15],[16],[17] The metabolic syndrome present in 34% of American adults yields a risk of heart [e-ijd.org]

• Vascular Disease

  Acanthosis nigricans in obese patients: presentations and implications for prevention of atherosclerotis vascular disease. Dermatol Online J. 2000;6(1):1. Kong AS, Williams RL, Rhyne R, et al. [winchesterhospital.org]

  Acanthosis nigricans in obese patients: Presentations and implications for prevention of atherosclerotic vascular disease Aaron S. Katz, M.D. 1, David C.Goff, M.D., Ph.D. 2 ,Steven R. [dermatology.cdlib.org]

  Acanthosis nigricans in obese patients: presentations and implications for prevention of atherosclerotic vascular disease. Dermatol Online J. 2000;6:1–24 19. Steinberger J, Daniels SR. [journals.lww.com]

• Skin Disease

  Last reviewed: 24 Oct 2022 Last updated: 19 Dec 2019 Summary A benign skin disease that often reflects underlying medical conditions. Most commonly associated with obesity and insulin resistance. [bestpractice.bmj.com]

  […] nigricans [nē′grikanz′] a skin disease characterized by hyperpigmented, velvety thickening of the skin, common in the neck, axilla, and groin. [medical-dictionary.thefreedictionary.com]

  A benign skin disease which often reflects underlying medical conditions. Most commonly associated with obesity and insulin resistance. [online.epocrates.com]

  Acanthosis nigricans is not a skin disease per se but a cutaneous sign of an underlying condition or disease. There are two important types of acanthosis : benign and malignant. [dermnetnz.org]

• Pruritus

  Pruritus (itching) may be present, particularly in acanthosis nigricans associated with malignancy ( paraneoplastic pruritus ). [dermnetnz.org]

  Occasionally, pruritus may be seen. The lesions often start as hyperpigmented macules and patches and progress into plaques that are palpable. [symptoma.com]

  Itching (pruritus) is common in acanthosis nigricans associated with paraneoplastic pruritus (malignancy). Acanthosis nigricans lesions occur sometimes on the mucous membranes of the laryngeal and nasal mucosa and esophagus, and the oral cavity. [mohsdermhouston.com]

  […] axillae, vulva, umbilicus, inner thighs, and groin weight gain generalised distribution sudden appearance of multiple seborrhoeic keratoses Other diagnostic factors age >40 years child/young adult female sex acrochordons (skin tags) acral distribution pruritus [bestpractice.bmj.com]

• Keratosis

  L57.0 ICD-10-CM Diagnosis Code L57.0 Actinic keratosis 2016 2017 2018 2019 Billable/Specific Code Applicable To Keratosis NOS Senile keratosis Solar keratosis nigricans L83 Papillomatosis - see also Neoplasm, benign, by site confluent and reticulated [icd10data.com]

  keratosis; nigricans, nigricans; keratosis, Acanthosis Nigricans Czech Acanthosis nigricans Finnish Acanthosis nigricans Korean 흑색 가시세포증(극세포증) Croatian ACANTHOSIS NIGRICANS Polish Rogowacenie ciemne Hungarian Acanthosis nigricans Norwegian Acanthosis [fpnotebook.com]

• Alopecia

  Darker Skin Tones Skin care secrets Hair care Hair loss Diseases & Conditions Acne Dark spots Dry skin Light spots Razor bumps Caring for Black hair Scalp psoriasis Weaves & extensions Central centrifugal cicatricial alopecia Frontal fibrosing alopecia [aad.org]

  […] the stratum spinosum, due to either an increased number or hypertrophy of cells. frictional acanthosis see acanthosis nigricans (below). acanthosis nigricans a skin disease of dogs characterized by hyperpigmentation, lichenification, seborrhea, and alopecia [medical-dictionary.thefreedictionary.com]

  […] polycystic ovary syndrome, acromegaly and congenital adrenal hyperplasia.2 Clinical Presentation and Differential Diagnosis In young women, hyperandrogenism manifests as oily skin, hirsutism, acne, menstrual irregularities and, in some cases, androgenic alopecia [aafp.org]

  Clinical Features of Autoimmunity NIH Series Our Patient ANA 83% + Hypoalbuminemia 63% + Leukopenia 63% + Elevated ESR 75% + Proteinuria 54% + Serum IgG 46% + High serum anti-dsDNA 33% - Elevated serum IgA 25% - Alopecia 25% - Skin rash 21% - Low C3 21% [cureus.com]

• Dermatitis

  Pagina 516 - Werner Y, Lindberg M: Transepidermal water loss in dry and clinically normal skin in patients with atopic dermatitis. Acta Derm Venereol (Stockh) 1985;65:102-105. ‎ [books.google.ro]

  […] rough, warty, or papillomatous locations axillae neck other skin folds less common Evaluation Laboratory values elevated glucose elevated insulin Screen for diabetes or malignancy if appropriate Differential Diagnosis Melasma Fungal infection Atopic dermatitis [step1.medbullets.com]

  Pellagra presents with photodistributed dermatitis (Casal's necklace) as well as diarrhea and dementia (the 3 Ds). Large plaque parapsoriasis tends to have diffusely distributed, scaly plaques. Pemphigus vegetans has verrucous ulcerated plaques. [visualdx.com]

  Differential Diagnosis (Other conditions with similar appearance) Atopic Dermatitis Becker nevus Candidiasis Erythrasma Giant melanocytic nevi Hypertrophic seborrheic keratosis Linear epidermal nevus Pemphigus vegetans Diagnosis Key Points *Diagnosis [ozarkderm.com]

  Azelaic acid (20 percent), kojic acid formulations, and alpha-hydroxy acids also have been useful in the treatment of melasma. 13 Side effects of all topical treatments include allergic and contact dermatitis, depigmentation of surrounding normal skin [aafp.org]

For patients with the adult onset of acanthosis nigricans, a basic workup for an underlying malignancy is carried out.

The individual also has to be screened for diabetes using a glycosylated hemoglobin level or glucose tolerance test.

The next screening to be done is for insulin resistance. One good screening test for insulin resistance is a plasma insulin level and this is often high in those with insulin resistance [8]. This test is the most sensitive in detecting a metabolic abnormality like this because younger patients do not have overt diabetes mellitus as well as a glycosylated hemoglobin level but they often show a high level of plasma insulin.

There is no choice treatment for acanthosis nigricans. The major aim of therapy is to ensure that the underlying disease process is corrected. The treatment of the lesions is only for cosmetic reasons. The burden of hyperkeratotic lesions is reduced by the correction of hyperinsulinemia [9]. Also, weight reduction in obesity associated acanthosis nigricans may lead to a resolution of the dermatosis.

For drug induced acanthosis nigricans, cessation of the inciting agent brings about a resolution of the condition. Nicotinic acid may be replaced by acipimox to bring about the regression of acanthosis nigricans even as the lipid profile continues to improve. Even if niacin is continued, dietary fish oil has been reported to be beneficial in patients with lipodystrophic diabetes and generalized acanthosis nigricans.

Benign acanthosis nigricans generally fades off after the cause is detected and treated. For patients with malignant acanthosis however, the prognosis is often poor. The malignancy associated with it is frequently advanced and in in general, the average survival of the patients is approximately 2 years [5].

The condition may be inherited genetically and it is associated with obesity. It can also be caused by endocrinopathies like hypothyroidism, acromegaly, polycystic ovary disease, insulin resistant diabetes or Cushing’s disease.

In the United States, the exact figure for the incidence of acanthosis nigricans is unknown. Within an unselected population of over 1400 children, the acanthosis changes were only visible amongst 7.1%. Obesity is closely linked with this disorder and so more than half of adults who weigh more than 200% of their ideal body weight have lesions that are closer to acanthosis nigricans.

Internationally, epidemiologic studies that were performed in Iran, United Arab Emirates and Japan all present significant increases in the resistance of insulin amongst obese patients that have the condition in comparison to matched obese controls without the disorder. This shows that acanthosis nigricans is a very useful marker when looking at insulin resistance among obese patients irrespective of geographic setting [3].

In patients with the benign form of acanthosis nigricans, there is very little complication on their skin lesions. Malignant complications on the other hand are often associated with significant complications because an aggressive tumor is often the underlying malignancy. For patients with the signs of malignant acanthosis, the average survival time is 2 year.

However, there have been cases where patients survived for another 12 years. Virtually all older patients with new-onset acanthosis nigricans have an associated internal malignancy.

This disorder is mostly seen amongst people with darker pigmentations of the skin. In whites, the prevalence is less than 1%. In Latinos, the prevalence was placed at 5.5% and in African Americans the prevalence is higher. It is placed at 13.3%. Amongst the Native American populace, one study showed that 34.2% of Cherokee patients aged 5-40 years with acanthosis nigricans. The figure increased to 73% amongst Cherokee patients with diabetes.
Unlike the benign form, malignant acanthosis nigricans doesn’t have any racial predilection.

The incidence of acanthosis nigricans is the same for both men and women so it doesn’t have a confirmed sex predilection.
The benign lesions of acanthosis nigricans may be seen at any age even at birth. However, it is found more commonly amongst the adult population.

Factors that stimulate epidermal keratinocyte and proliferation of the dermal fibroblast have been pointed out as the main cause of fibroblast protection. With the benign form of acanthosis nigricans, the epidermal cell propagation is incited by insulin or insulin growth like factor [4]. Other mediators that have been proposed include tyrosine kinase receptors and fibroblast growth receptor.

Insulin may exert potent proliferative effects via high-affinity binding to the IGF-1 receptors under high concentrations. Additional free IGF-1 levels may get elevated in obese patients with hyperinsulinemia. This leads to accelerated cell growth and differentiation.

As suggested by the predilection of acanthosis nigricans, perspiration or friction may equally play a contributory role

The help reduce chances of getting acanthosis nigricans, individuals are advised to take conscious steps towards maintaining a healthy body weight. Insulin levels should also be checked regularly to ensure that it is kept at a normal level [10].

This is a skin condition that is characterized by areas of dark and velvety discolorations around creases and body folds. The affected area of skin thickens and in some cases, smells bad. In many cases, acanthosis nigricans is seen around the armpit, neck and groins [1].

This type of changes in the skin is mostly seen in individuals who are either obese or have diabetes. When seen in children, it means that they have an increased risk of developing type 2 diabetes. On rare occasions, acanthosis nigricans depicts the possibility of a cancerous tumor in an internal organ like the stomach or liver.

Even though Addison may have come across a case of acanthosis nigricans in 1885, misdiagnosing it as the Addison disease, the first case of acanthosis nigricans was recorded in 1889 in Germany. It was described by Unna and Pollitzer [2]. By 1909, acanthosis nigricans has been described in approximately 50 patients and it was suspected to be closely linked with internal malignancy. It was in 1976 that Khan et al published their landmark study in which the relationship between acanthosis nigricans and insulin was first described. In 2000, the American diabetes association proved acanthosis nigricans as a formal risk factor for the development of diabetes amongst children.

Keep in mind that acanthosis nigricans is not a skin disease. Instead it is a sign of an underlying problem. If the acanthosis nigricans case you are looking at has been proven by medical experts to be on the basis of insulin resistance, treating this metabolic abnormality will bring about an improvement in the appearance of the skin. With the right dietary changes and weight loss, acanthosis nigricans can be forced to regress almost completely [11].

1. Sinha S, Schwartz RA. Juvenile acanthosis nigricans. J Am Acad Dermatol. Sep 2007;57(3):502-8.
2. Higgins SP, Freemark M, Prose NS. Acanthosis nigricans: a practical approach to evaluation and management. Dermatol Online J. Sep 15 2008;14(9):2.
3. Berk DR, Spector EB, Bayliss SJ. Familial acanthosis nigricans due to K650T FGFR3 mutation. Arch Dermatol. Sep 2007;143(9):1153-6.
4. Sharda S, Panigrahi I, Gupta K, Singhi S, Kumar R. A newborn with acanthosis nigricans: can it be Crouzon syndrome with acanthosis nigricans?. Pediatr Dermatol. Jan 1 2010;27(1):43-7.
5. Krawczyk M, Mykala-Ciesla J, Kolodziej-Jaskula A. Acanthosis nigricans as a paraneoplastic syndrome. Case reports and review of literature. Pol Arch Med Wewn. Mar 2009;119(3):180-3.
6. Rafalson L, Eysaman J, Quattrin T. Screening obese students for acanthosis nigricans and other diabetes risk factors in the urban school-based health center. Clin Pediatr (Phila) 2011; 50:747.
7. Litonjua P, Piñero-Piloña A, Aviles-Santa L, Raskin P. Prevalence of acanthosis nigricans in newly-diagnosed type 2 diabetes. Endocr Pract 2004; 10:101.
8. Nguyen TT, Keil MF, Russell DL, et al. Relation of acanthosis nigricans to hyperinsulinemia and insulin sensitivity in overweight African American and white children. J Pediatr 2001; 138:474.
9. Stuart CA, Pate CJ, Peters EJ. Prevalence of acanthosis nigricans in an unselected population. Am J Med 1989; 87:269.
10. Stuart CA, Driscoll MS, Lundquist KF, et al. Acanthosis nigricans. J Basic Clin Physiol Pharmacol 1998; 9:407.
11. Brickman WJ, Binns HJ, Jovanovic BD, et al. Acanthosis nigricans: a common finding in overweight youth. Pediatr Dermatol 2007; 24:601.