Velvety Perioral Enigma

An obese girl in her teens, with a body mass index of 28.4 kg/m2, presented to us with dark brown hyperpigmented plaques over the perioral region with velvety texture for 5 years. There was no involvement of the axillae or groin with any lesions of similar morphology and no family history of metabolic syndrome. Dermoscopy revealed the presence of linear crista cutis, sulcus cutis, and hyperpigmented dots in crista cutis, consistent with acanthosis nigricans (AN) [Figure 1a and b]. Skin biopsy was deferred due to cosmetic concerns. The metabolic profile including fasting lipid profile, blood sugars, and insulin levels revealed no abnormal findings, thereby excluding metabolic syndrome. The patient denied skin biopsy due to cosmetic reasons.Figure 1: (a) Presence of dark brown hyperpigmented plaques with velvety texture over the perioral region (b) Dermoscopy revealed the presence of linear crista cutis (blue star), sulcus cutis (black arrow), and hyperpigmented dots in crista cutis (red circle), consistent with acanthosis nigricans. Dermlite 4 (Polarised), ×10Facial AN typically features velvety dark plaques over the zygomatic-malar areas, with perioral involvement being uncommon (14%).[1] It is predominantly linked to insulin resistance, diabetes, obesity, and metabolic syndrome. Other etiologies include drugs, hereditary, syndromic, and malignancies. Other differentials in such a case include seborrheic melanosis and perioral dermatitis. While the former presents as localized hyperpigmentation over the alar grooves and labiomental crease with arborizing vessels and yellow scales on dermoscopy, the latter usually presents as multiple inflammatory papulovesicles sparing vermilion border of lips. To conclude, facial AN needs to be considered in differential diagnosis of perioral pigmentation amidst the rise in the prevalence of metabolic syndrome in adolescents. Declaration of patient consent The authors certify that they have obtained all appropriate consent forms, duly signed by the parent(s)/guardian(s) of the patient. In the form, the parent(s)/guardian(s) has/have given his/her/their consent for the images and other clinical information of their child to be reported in the journal. The parents understand that the names and initials of their child/children will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.