Facial Melanosis: A Comprehensive Review of Uncommon and Common Presentations with Personal Experience

Facial melanoses (FMs) encompass a diverse group of disorders characterised by altered facial pigmentation, particularly prevalent in individuals with darker skin types, such as the Indian population. While common causes like melasma, post-inflammatory hyperpigmentation, and lichen planus pigmentosus are well documented in the literature, this review emphasises the lesser-known and uncommon causes of FM. These include facial acanthosis nigricans, maturational hyperpigmentation, frictional facial melanosis, and seborrheic melanosis, which are frequently observed in Indian populations but remain underrecognised and understudied. The aetiology of FM is multifactorial, involving genetic predisposition, racial factors, ultraviolet radiation, and exposure to photosensitising chemicals and allergens. Uncommon causes often present unique diagnostic challenges and are frequently misdiagnosed due to their overlapping clinical features. Diagnosis relies on clinical evaluation, supported by Wood's lamp examination, dermoscopy, and, in some cases, skin biopsy. FM can be classified into brown, blue, or mixed hypermelanosis based on the location and nature of melanin deposition. Management of these uncommon conditions is complex and requires a nuanced approach. Photoprotection remains a cornerstone of therapy, alongside topical depigmenting agents, chemical peels, and laser or light-based interventions. However, the risk of post-inflammatory hyperpigmentation in richly pigmented skin necessitates cautious and individualised treatment strategies. The lack of standardised guidelines for these uncommon causes further complicates management, underscoring the need for tailored therapeutic approaches. This review highlights the clinical significance of recognising and addressing uncommon causes of FM, which significantly impact patients' quality of life and psychosocial well-being. Enhanced awareness, further research, and the development of evidence-based treatment protocols are essential to improve outcomes for patients with these understudied conditions. By focussing on these uncommon causes, this review aims to fill a critical gap in the literature and provide a comprehensive resource for clinicians managing facial melanoses in skin of colour. Such comprehensive articles are lacking in literature.