A healthy 37-year-old woman presented to the clinic with a 1-year history of progressive asymptomatic hyperpigmented macules on the lips and longitudinal hyperpigmentation of the left thumb extending to the cuticle. There was no relevant drug or positive family history or evidence of other pigmented lesions. On examination, there was linear, brownish, reticular pattern on both inner aspect of her lips and longitudinal melanonychia in the left thumb extending to the cuticle on the middle aspect of the nail. Laboratory tests, Chest X-ray and abdominal ultrasound were normal. Colonoscopic findings were negative for any gastrointestinal pathology or tumorous formations associated with oral hyperpigmentations. Based on the endocrinologist's exam adrenal insufficiency was ruled out and histological examination of the lip lesions revealed non-specific changes such as acantosis and hyperpigmentation of the basal layer. By excluding the other differentials, diagnosis of Laugier-Hunziker syndrome was made. Laugier-Hunziker syndrome is a benign chronic progressive asymptomatic hyperpigmented macules on the lips and buccal mucosa and often is associated with longitudinal melanonychia (A). The main differential diagnoses are drug induced hyperpigmentation, racial pigmentation, smoker’s melanosis, Addisons disease and Peutz-Jeghers syndrome (B). As a diagnosis of exclusion Laugier-Hunziker syndrome always should be considered in the differential diagnosis of patients with mucocutaneous and nail hyperpigmentation without any systemic symptoms, specially in the middle-aged groups (A,B). Therefore, its diagnosis can easily exclude other severe pigmentary disorders and avoid unnecessary diagnostic procedures. Treatment is not necessary exept for cosmetic purposes (B).

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Corresponding author
Amir Feily, Department of Dermatology, Jahrom University of Medical Sciences, Jahrom, Iran (dr.feily@yahoo.com)