Acanthosis nigricans: To be or not to be afraid (Review)

Abstract

Acanthosis nigricans (AN), a skin disorder with high prevalence, represents a dermatological condition with esthetic implications, but otherwise mild symptoms. For any clinician, it is in fact the tip of the iceberg, leading him/her to investigate what lies beneath the surface, since AN points to a systemic problem or disease: metabolic disorder (most frequently), endocrine syndrome, medication side effects, malignancy, and genetic factors. Sometimes, it is the first observed sign of a malignancy or of diabetes mellitus, especially in patients with chronic metabolic disorder; therefore, it is not to be taken lightly. The present review summarizes the information in literature regarding the etiopathogenesis of AN. We propose a new classification that aims to better organize the different types of AN, with implications on the extent and urgency of the investigation plan, as well as various therapeutic algorithms. Therapy options are also presented, both systemic treatments that target the underlying disease, and local ones for esthetic reasons.

Acanthosis nigricans: A review

“…Hyperinsulinemia, as noted in obesity and type 2 diabetes, can directly activate IGF‐1 receptors on skin cells and increase IGF‐1 blood levels by decreasing circulating levels of IGF binding protein 1 and 2 (thus increasing free IGF‐1 level in tissues) 7 …”

“…The association of AN with rare syndromes has been described: Barter syndrome, 24 Benign encephalopathy, 25 Bloom syndrome, 26 Chondrodystrophy with dwarfism, 27 Costello syndrome, 28 Dermatomyositis, 29 Familial pineal body hypertrophy, 30 Gigantism, 7 Hashimoto thyroiditis, 31 Hirschowitz syndrome, 32 Lipoatrophic diabetes mellitus, 33 Lupoid hepatitis, 34 Lupus erythematosus, 35 Phenylketonuria, 36 Pituitary hypogonadism, 37 Pseudoacromegaly, 38 Prader‐Willi syndrome, 39 Rud syndrome, 40 Scleroderma, 41 Type A syndrome (HAIR‐AN syndrome), 42 Werner syndrome, 43 Wilson syndrome 44 …”

Diffuse Esophageal Squamous Papillomatosis: A Rare Disease Associated with Acanthosis Nigricans and Tripe Palms

“…AN is a well-known skin manifestation of systemic conditions. It appears as a thickening hyperpigmentation, with velvety texture of the skin, mainly involving skin folds, particularly in the neck and axilla [ 4 ]. Although most cases of AN are associated with obesity and insulin resistance, other causes have been described, with paraneoplastic AN being the most worrisome condition.…”

“…Most lesions are solitary [ 2 , 3 ]; nonetheless, diffuse esophageal squamous papillomatosis involving the entire esophagus is extremely rare. Acanthosis nigricans (AN) with tripe palms is a well-known skin manifestation of systemic conditions, as well as internal malignancy [ 4 ]. There have been reports of this paraneoplastic condition's association with orocutaneous papillomatosis, but investigations into its relationship with diffuse esophageal papillomatosis are scarce.…”

COVID‑19 and diabetes mellitus: Unraveling the hypotheses that worsen the prognosis (Review)

“…The most recognized cutaneous manifestation in diabetes, present in 74% of obese patients with diabetes mellitus is Acanthosis nigricans (AN), a hyperpigmented velvety thickening of skin folds (86). Moreover, the presence of AN could be a good prognostic indicator for development of hyperinsulinemia in newly diagnosed diabetes mellitus with a possible genetic predisposition or increased sensitivity of the skin to increased plasma insulin levels (87,88). Benign AN type 2 is linked to T2DM, initially starting insidiously with hyperpigmentation while pseudo-AN type 3 is associated with metabolic syndrome.…”