The Laugier-Hunziker syndrome

Abstract

We describe a 46-year-old Hispanic woman who was incidentally found to have hyperpigmentation of the oral mucosa and nails during a routine full body skin examination. The patient reported having these changes for years with no symptoms. A diagnosis of the Laugier-Hunziker syndrome (LHS) was made. LHS is an acquired, benign condition characterized by pigmentary skin changes involving the oral mucosa and is often associated with longitudinal melanonychia.

The Laugier-Hunziker syndrome (LHS) is an acquired, benign pigmentary skin condition involving the oral mucosa, often associated with longitudinal melanonychia. It is a diagnosis of exclusion, and other systemic conditions should be excluded prior to making a diagnosis. We describe the case of a patient who was diagnosed with LHS during a routine skin examination.

CASE DESCRIPTION

A 46-year-old Hispanic woman was incidentally noted to have four asymptomatic, hyperpigmented macules on the inner aspect of the lower lip (Figure 1) and one hyperpigmented macule on the inner aspect of the upper lip during a routine total body skin exam. The patient denied any symptoms related to any of these lesions. She was also found to have longitudinal hyperpigmented changes of the fingernails extending to the cuticle, more common on the lateral aspect of the nails (Figure 2). Similar findings were also present on the fifth digit of the right foot. The patient reported that she had had these nail changes for several years. There was no associated nail dystrophy, and she denied any symptoms related to the nail findings. The remainder of the physical exam showed no evidence of other pigmented lesions. She was otherwise healthy and not currently taking any medications.

Figure 1.

Four hyperpigmented macules on the inner aspect of the lower lip.

Figure 2.

Longitudinal hyperpigmentation of the fingernails.

DISCUSSION

LHS, also known as idiopathic lenticular mucocutaneous pigmentation, was first described in 1970 (1). It is characterized by a number of asymptomatic, hyperpigmented mucocutaneous macules whose color ranges from brown to black (1). Lesions most commonly involve the buccal mucosa and lips, but the gums, tongue, palate, fingers, toes, neck, and abdomen can also be involved. Nails are affected in about 60% of cases, and findings include longitudinal stripes affecting the nail plate (2). The diagnosis of LHS is frequently made clinically and is a diagnosis of exclusion (3). Biopsy of the lesions can be performed to confirm the diagnosis, and histopathologic changes associated with LHS show increased basal layer pigmentation with a normal number and morphologic appearance of melanocytes (2).

Prior to making the diagnosis of LHS, it is important to exclude other associated systemic conditions including the Peutz-Jeghers syndrome (PJS) and Addison's disease. PJS is an autosomal dominant genetic disorder that shares clinical features with LHS and is an important differential diagnosis to exclude due to its increased risk of malignancy (4). PJS is characterized by hamartomatous gastrointestinal polyposis and hyperpigmentation of the skin and mucous membranes and is associated with an increased risk of both intestinal and extraintestinal malignancies. Diagnosis of PJS is made based on the presence of polyps in the gastrointestinal tract and a family history of the disorder, neither of which was present in our patient. Addison's disease, an endocrine disorder caused by insufficient production of cortisol and aldosterone, is characterized by increased pigmentation of the knuckles, skin creases, and mucous membranes and should also be considered in the differential (5). Other systemic findings include hypotension, dehydration, and abdominal pain, which were all absent in our patient. Other less common conditions that should be considered in the differential for hyperpigmentation include the McCune-Albright syndrome, drug-induced hyperpigmentation (tetracyclines, antimalarials, and chemotherapeutics), and the Gardener syndrome (2).

Our patient presented with the characteristic features of LHS. With the lack of systemic symptoms and a prior colonoscopy showing no evidence of polyps, PJS and Addison's disease were ruled out. LHS is known to be a benign disorder with no systemic manifestations and no increased risk for malignancy (5). Treatment for LHS is usually sought for cosmetic reasons, and possible therapeutic options include laser therapy and cryosurgery (2). Our patient did not have any cosmetic concerns, and as such, no treatment was given.