The etiology of this disorder remains unclear. Histopathological examinations of affected individuals suggest a functional alteration of melanocytes, which appear to be activated to continually synthesize higher amounts of melanin in a chronic fashion. However, the initial stimulus that induces this melanocyte activation is unknown.
Recognizing that this syndrome may mimic other pigmentary disorders, it is important to rule out those with potential for malignant transformation or other clinical implications. As a benign condition itself, the macular lesions of this syndrome do not require therapeutic intervention, although treatment may be pursued for cosmesis.
K13.70 – Unspecified lesions of oral mucosa
238706002 – Laugier-Hunziker syndrome
Differential diagnosis includes all causes of oral melanotic macules.
Rule out syndromes with systemic involvement, including:
- Peutz-Jeghers syndrome – May present with gastrointestinal symptoms, as well as a positive family history. Although oral lesions typically persist, macules on the skin develop in early childhood and may fade over time. No associated nail changes.
- McCune-Albright syndrome – Often accompanied by endocrine abnormalities and bony defects. Presents with pigmented macules that develop in infancy, compared with middle age in LHS. Oral melanosis is a feature.
- Carney complex
Skin, Mucous Membrane, and Nail Pigmentation
Addison disease – Pigmentation may be generalized or accentuated on extensor surfaces. Palms and nails may also be affected. Often accompanied by systemic signs and symptoms like hypotension, weakness, and fatigue. Can differentiate with serum cortisol and adrenocorticotropic hormone (ACTH) levels.
Differential diagnosis includes all the causes of longitudinal melanonychia.
Last Updated: 02/27/2017