Cutaneous and mucosal lichen planus: a comprehensive review of clinical subtypes, risk factors, diagnosis, and prognosis

Abstract

Lichen planus (LP) is a chronic inflammatory disorder that most often affects middle-aged adults. LP can involve the skin or mucous membranes including the oral, vulvovaginal, esophageal, laryngeal, and conjunctival mucosa. It has different variants based on the morphology of the lesions and the site of involvement. The literature suggests that certain presentations of the disease such as esophageal or ophthalmological involvement are underdiagnosed. The burden of the disease is higher in some variants including hypertrophic LP and erosive oral LP, which may have a more chronic pattern. LP can significantly affect the quality of life of patients as well. Drugs or contact allergens can cause lichenoid reactions as the main differential diagnosis of LP. LP is a T-cell mediated immunologic disease but the responsible antigen remains unidentified. In this paper, we review the history, epidemiology, and clinical subtypes of LP. We also review the histopathologic aspects of the disease, differential diagnoses, immunopathogenesis, and the clinical and genetic correlations.

Figure 1

(a) Classic CLP: violaceous Papules on the dorsal hand and volar wrist (courtesy of Dr. Omid Zargari); (b) hypertrophic CLP: centrally eroded hyperkeratotic plaques involving the lower leg; (c) vesiculobullous CLP: vesicles and bullae on right and left ankles and lower legs (courtesy of Dr. Peter Lynch); (d) actinic CLP: hyperpigmented Papules and plaques on the dorsal hands (courtesy of Dr. Peter Lynch); (e) annular CLP: reticulated white striae involving the glans penis (courtesy of Dr. Omid Zargari); (f) atrophic CLP: hyperpigmented macules and patches on the arm (courtesy of Dr. Peter Lynch); (g) zosteriform CLP: linearly oriented confluent violaceous Papules on the arm; (h) nail CLP: longitudinal ridging of the fingernails (courtesy of Dr. Peter Lynch); (i) nail CLP: dorsal pterygium of the thumbnail; (a), (b), (e), (g), and (i) are reprinted with permission from [50]. CLP, cutaneous lichen planus.

Figure 2

(a) Reticular OLP: reticulated white striae of the lower lip proper; (b) plaque-type OLP: confluent white reticulated plaques of the lateral tongue; (c) erosive OLP: superficial erosions and white striae of the lower lip proper (courtesy of Dr. Peter Lynch); (d) vulvar LP: superficial erosions at the vulvar introitus with fusion of the labia minora and vaginal stenosis; Figures 1(a) and 1(b) are reprinted with permission from [50]. OLP, oral lichen planus.