ABSTRACT
Lichen planus (LP) is a T-cell-mediated autoimmune disorder that can involve the skin, mucous membranes, hair, and nails. Nail involvement may occur in 1% to 10% of cases of lichen planus, mostly in the setting of widespread cutaneous disease. Nail lichen planus (NLP) usually presents in association with cutaneous, mucosal, or scalp lesions but may be the sole manifestation of the disease. It may involve the nail matrix, proximal and lateral nail folds, nail bed, and/or the hyponychium. Dorsal pterygium and trachonychia are characteristic nail lesions of lichen planus. Diagnosis of NLP is based on clinical examination, onychoscopy, and histopathology. Treatment is difficult and various therapeutic modalities have been tried, which includes topical and intralesional steroid, topical calcineurin inhibitor, and retinoids. This chapter describes pathophysiology, clinical features, diagnosis, and treatment modalities of NLP.
