INTRODUCTION
Periorbital melanosis (PM), commonly known as dark circles, is a benign condition with a clinical appearance of bilateral periocular homogeneous dark brown pigmentation. It is of great cosmetic concern as it makes the patient look tired all the time. The etiology is multifactorial, classifying it into two clinical types – primary and secondary. Primary type, also known as idiopathic hyperchromia of orbital region, is not associated with any systemic or local disease, whereas the secondary type has an underlying cause.[1] One such cause is acanthosis nigricans (AN) which manifests as dark, velvety, and thickened skin with symmetrical distribution over the neck, axillae, other flexural regions of the body, and rarely the face.[2] Periorbital distribution of AN, a subset of facial AN, mimics PM. Facial AN is proposed as a morphological marker of metabolic syndrome.[2],[3]
CASE REPORT
A 53-year-old menopausal woman came with a complaint of bilateral periorbital darkening [Figure 1], which was asymptomatic and gradually progressive over the past 5 years. The darkened area had a velvety texture with wrinkling and laxity [Figure 2]. On further examination, the darkening of axillae was also noted [Figures 3 and 4]. There was no history of atopy, relevant drug intake before the onset of the complaint, contact dermatitis, or the use of topical steroids. Family history in the patient's mother was significant for PM, long-standing uncontrolled diabetes mellitus, cardiovascular disease, and death due to cerebrovascular accident.
Figure 1: Bilateral periorbital darkening
Figure 2: Velvety texture with wrinkling and laxity
Figure 3: Darkening of right axilla
Figure 4: Darkening of left axilla
On general examination, her blood pressure was 146/90 mmHg in the right upper limb in supine position, and she was obese (Body Mass Index 30.4 kg/m2) interpreted according to the classification used by the World Health Organization.[4] Waist circumference was measured to be 39.5 inches.
The blood investigations showed fasting blood glucose levels 128 mg/dL (normal is <100 mg/dl), glycated hemoglobin (HbA1c) 7.8%, serum triglycerides 160 mg/dl (normal is <150 mg/dl), serum high-density lipoprotein (HDL) cholesterol 38.8 mg/dl (normal range is 40-60 mg/dl) and thyroid profile was within normal limits.
She was also referred to a physician for having a 1-month long history of chest discomfort. An electrocardiogram was carried out, wherein T-wave inversions were observed; however, stress test was negative at that moment.
Based on the above findings, she fulfilled the criteria of metabolic syndrome, defined by the revised National Cholesterol Education Program adult treatment panel III criteria (2005 revision).[5]
DISCUSSION
Periorbital hyperpigmentation is multifactorial, and thus the mainstay of treatment is the correction of the underlying cause. In this case, along with weight reduction, the patient should be advised oral agents to manage insulin resistance such as metformin.[6] Additionally, options for cosmetic resolution should be strongly considered for patient satisfaction. These include topical agents such as hydroquinone, kojic acid, azelaic acid, retinoids, salicylic acid, podophyllin, urea, and calcipotriol; lasers and chemical peels (trichloroacetic acid peel).[6],[7]
Being quite a common dermatological complaint, patients of PM are mostly bothered by its aesthetically unappealing appearance. However, what we need to be concerned about as physicians is the possibility of underlying metabolic syndrome. What presents as dark circles could be a manifestation of AN, a cutaneous marker of insulin resistance.[1] In such patients of PM along with clinical features of AN, metabolic syndrome should be kept in mind and they should be investigated and counselled accordingly. We have reported one such case earlier and have also witnessed a series of similar patients (unpublished data).[8] However, larger multicentric studies are required to investigate the association between PM and metabolic syndrome.
Conflicts of interest
There are no conflicts of interest.
Informed consent
Patient's informed consent for the publication of the case details and photographs was taken.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Funding
Nil.
Author's contribution
The authors confirm contribution to the paper as follows: Zawar VP: Conceptualization, title framing, literature search, drafting and critical revision of the article for important intellectual content and final approval of the version to be published. Chokshi HM: Literature search, collection, follow up, analysis and interpretation of data and manuscript writing.
REFERENCES
1. Thappa DM, Chandrashekar L, Rajappa M, Usha R, Muthupandi K, Mohanraj PS, et al Assessment of patients with
periorbital melanosis for hyperinsulinemia and Insulin Resistance Indian Dermatol Online J. 2021;12:244–9
2. Panda S, Das A, Lahiri K, Chatterjee M, Padhi T, Rathi S, et al Facial
acanthosis nigricans: A morphological marker of
metabolic syndrome Indian J Dermatol. 2017;62:591–7
3. Shah VH, Rambhia KD, Mukhi JI, Singh RP, Kaswan P. Clinico-investigative study of facial
acanthosis nigricans Indian Dermatol Online J. 2022;13:221–8
4. Weir CB, Jan A. BMI Classification Percentile and Cut off Points StatPearls. 2022 Treasure Island (FL) StatPearls Publishing
5. Huang PL. A comprehensive definition for
metabolic syndrome Dis Model Mech. 2009;2:231–7
6. Patel NU, Roach C, Alinia H, Huang WW, Feldman SR. Current treatment options for
acanthosis Nigricans Clin Cosmet Investig Dermatol. 2018;11:407–13
7. Sarkar R, Ranjan R, Garg S, Garg VK, Sonthalia S, Bansal S. Periorbital hyperpigmentation: A Comprehensive review J Clin Aesthet Dermatol. 2016;9:49–55
8. Zawar V, Daga S, Pawar M, Kumavat S. Periorbital pigmentation: An alarming sign of
metabolic syndrome J Cosmet Dermatol.. 2019;18:1584–6