Mystery behind labial and oral melanotic macules: Clinical, dermoscopic and pathological aspects of Laugier-Hunziker syndrome

Abstract

Labial and oral melanotic macules are commonly encountered in a broad range of conditions ranging from physiologic pigmentation to a sign of an underlying life-threatening disease. Although Laugier-Hunziker syndrome (LHS) shares some features of labial and oral pigmentation with a variety of conditions, it is a benign and acquired condition, frequently associated with longitudinal melanonychia. Herein, the demographic, clinical, dermoscopic, and pathological aspects of LHS were reviewed comprehensively. The important differential diagnoses of mucocutaneous and nail pigmentation are provided. An accurate diagnosis is crucial to design a reasonable medical strategy, including management options, malignant transformation surveillance, and psychological support. It is important that clinicians conduct long-term follow-up and surveillance due to the potential risks of malignant transformation and local severe complications in some conditions.

Laugier–Hunziker Syndrome in an 8-Year-Old Boy with Scleral Melanocytosis, Lingual Pigmentation, Labial Pigmentation, and Melanonychia Striata

“…Laugier-Hunziker syndrome, a benign disease with no systemic manifestations, is characterized by asymptomatic mucocutaneous hyperpigmentation and melanonychia striata with no underlying systemic abnormalities [1]. Mucosal involvement in Laugier-Hunziker syndrome is characterized by asymptomatic, gray, light brown, brown, brown-black, blue-black, or black macules on the oral and genital mucosa [1,3,6]. e macules usually have welldefined margins which may be oval, lenticular, linear, or irregular in shape and less than 5 mm in diameter [3,6,8,9].…”

“…Mucosal involvement in Laugier-Hunziker syndrome is characterized by asymptomatic, gray, light brown, brown, brown-black, blue-black, or black macules on the oral and genital mucosa [1,3,6]. e macules usually have welldefined margins which may be oval, lenticular, linear, or irregular in shape and less than 5 mm in diameter [3,6,8,9]. ese macules may be solitary or multiple and sometimes confluent [9].…”

“…In the mean time, we suggest ocular pigmentation be grouped under the umbrella "essential melanotic pigmentation of mucosa." Melanonychia striata is present in approximately 50 to 60% of patients with Laugier-Hunziker syndrome and may present as single, double, or multiple longitudinal stripes that runs along the longitudinal axis of the nail from the proximal nail fold to the distal nail plate or, less commonly, as homogeneous pigmentation involving one half of the nail or complete nail [3,6,9,18]. e coloration can be tan, brown, gray, or black [18].…”

“…e coloration can be tan, brown, gray, or black [18]. Fingernails are affected more often than toenails [3,5]. Melanonychia striata is more common in the thumb.…”

“…e condition was first described in 1970 by Laugier and Hunziker who reported five patients with acquired macular hyperpigmentation of the lips and oral mucosa and two of these patients displayed hyperpigmentation of the fingernails [2]. Since the description of the disorder, approximately 200 cases have been reported [3,4]. e majority of cases have been reported in adults.…”