Acanthosis Nigricans: Pointer of Endocrine Entities

Abstract

Acanthosis nigricans (AN) has been reported in relation to insulin resistance (IR). We aim to review AN through an endocrine and metabolic perspective focusing on IR in association with metabolic complications such as obesity, diabetes mellitus (DM), and metabolic syndrome (MS) with/without polycystic ovary syndrome (PCOS). We revised English papers on PubMed covering publications from the last 5 years. The current prevalence of AN varies from 4.5 to 74% (or even 100%, depending on the studied population), with equal distribution among females and males. Despite higher incidence with an age-dependent pattern, an alarming escalation of cases has been noted for obesity and MS in younger populations . Most frequent IR-associated sites are the neck, axilla, and knuckles, but unusual locations such as the face have also been reported. Quantitative scales such as Burke have been used to describe the severity of the dermatosis, particularly in correlation with IR elements. Dermoscopic examination are required, for instance, in cases with sulcus cutis, hyperpigmented spots, crista cutis, and papillary projections. A skin biopsy may be necessary, but it is not the rule. Both IR that clinically manifests with or without obesity/MS correlates with AN; most studies are cross-sectional, with only a few longitudinal. The approach varied from screening during school periodic checkups/protocols/programs to subgroups of individuals who were already known to be at high cardio-metabolic risk. AN was associated with type2DM, as well as type 1DM. Females with PCOS may already display metabolic complications in 60–80% of cases, with AN belonging to the associated skin spectrum. AN management depends on underlying conditions, and specific dermatological therapy is not generally required, unless the patient achieves metabolic control, has severe skin lesions, or desires cosmetic improvement. In IR cases, lifestyle interventions can help, including weight control up to bariatric surgery. In addition, metformin is a key player in the field of oral medication against DM type 2, a drug whose indication is extended to PCOS and even to AN itself, outside the specific panel of glucose anomalies. In terms of cosmetic intervention, limited data have been published on melatonin, urea cream, topical retinoids, vitamin D analogs, or alexandrite laser. In conclusion, awareness of IR and its associated clinical features is essential to provide prompt recognition of underlying conditions. AN represents a useful non-invasive surrogate marker of this spectrum in both children and adults. The pivotal role of this dermatosis could massively improve endocrine and metabolic assessments.

Connections between serum Trimethylamine N-Oxide (TMAO), a gut-derived metabolite, and vascular biomarkers evaluating arterial stiffness and subclinical atherosclerosis in children with obesity

“…The multiple regression showed a significant influence of the blood parameters investigating IR (HOMA-IR, fasting glucose, VAI, and TyG index) on serum TMAO, but only HOMA-IR and fasting glucose were confirmed as independent predictors of TMAO. Moreover, when investigating the presence of acanthosis nigricans as a marker of insulin resistance ( 62 ), this study showed that an increase in TMAO is associated with an increase in the probability of the presence of acanthosis nigricans. Insulin resistance itself is an aggravating factor for the progression of vascular disruptions in obese children ( 137 ).…”

“…Tanner stages were determined for each participant (Tanner 1 represents pre-puberty; Tanner 2-4 represents puberty; Tanner 5 represents post-puberty) ( 61 ). The presence of acanthosis nigricans was noted ( 62 ). Post-pubertal girls were asked whether they had regular or irregular menses.…”

Comparison of the Outcome of Treatment of 15% Trichloroacetic Acid versus Topical 0.05% Tretinoin in the Treatment of Acanthosis Nigricans at Tertiary Care Hospital, Karachi

“…Nevertheless, the study had limitations, including a relatively small sample size and a short follow-up period, which may limit the generalizability of the results. Additionally, the occurrence of adverse effects like pruritus and redness in the TCA group and burning and skin peeling in the Tretinoin group highlight the importance of considering patient tolerance and comfort in treatment selection (21).…”

Diabetes mellitus and its skin manifestations - dermatology for diabetologists

“…Diagnosis, in most cases, should be limited to dermatoscopy; however, in some cases, a biopsy may be indicated to differentiate dark acanthosis from other discolorations. [2] [8] [17] Hidradenitis suppurativa (inverse acne) is a chronic inflammatory skin disease that begins in hair follicles and, in collaboration with bacterial infection, leads to the formation of painful inflammatory nodules, abscesses, and skin fistulas. It is most commonly located in areas where the skin rubs against itself, such as the underarms, breasts, and groin, but as the disease progresses, it can affect body regions such as the neck, limbs, or skin behind the ears.…”