SynopsisCodesLook ForDiagnostic PearlsDifferential Diagnosis & PitfallsBest TestsManagement PearlsTherapyReferences

View all Images (56)

Lichenoid keratosis
Other Resources UpToDate PubMed

Lichenoid keratosis

Contributors: Jeffrey M. Cohen MD, Erik Domingues MD, Belinda Tan MD, PhD, Sarah Hocker DO, Nikki Levin MD, Susan Burgin MD
Other Resources UpToDate PubMed


Lichenoid keratosis, also known as benign lichenoid keratosis (BLK), solitary lichenoid keratosis (SLK), lichen planus-like keratosis (LPLK), solitary lichen planus, or involuting lichenoid plaque, is an asymptomatic or mildly pruritic pink papule or plaque commonly found on sun-exposed areas. While lichenoid keratoses can appear anywhere on the skin, the most common location is the trunk. These lesions also frequently appear on extremities.

Clinically, lichenoid keratosis may simulate an actinic keratosis, basal cell carcinoma (eg, nodular or superficial), squamous cell carcinoma in situ, seborrheic keratosis, or a pigmented or amelanotic melanoma, whereas histologically it is almost identical to lichen planus.

The pathogenesis of lichenoid keratosis is not entirely understood, but it is thought to represent an inflammatory reaction occurring in a preexisting solar lentigo, seborrheic keratosis, or actinic keratosis.

Lichenoid keratoses are usually asymptomatic but may be slightly pruritic. Patients occasionally report that the lesion has changed, prompting examination of the lesion and biopsy. On average, the lesion has been present for 6 months at the time of diagnosis.

Most lichenoid keratoses are erythematous / pink, although some are violaceous or hyperpigmented. They are typically solitary and range in size from 3-19 mm in diameter. They may be scaly, pearly, or indurated.

Lichenoid keratoses often involute spontaneously over a period of months.


L43.9 – Lichen planus, unspecified

403198004 – Lichenoid actinic keratosis

Look For

Subscription Required

Diagnostic Pearls

Subscription Required

Differential Diagnosis & Pitfalls

  • Lichenoid Actinic keratosis
  • Lichen planus – Presents with multiple pruritic, polygonal purple plaques, whereas lesions of lichenoid keratosis are usually solitary. Look for Wickham striae and oral white lacy reticulate plaques on buccal mucosa (see Oral lichen planus).
  • Basal cell carcinoma – Nodular basal cell carcinoma presents with a solitary shiny, red nodule with large telangiectatic vessels that may show ulceration or bleeding; Superficial basal cell carcinoma presents with flat, well-demarcated erythematous plaques resembling eczema but unresponsive to eczema therapies. Biopsy is diagnostic.
  • Cutaneous squamous cell carcinoma – A verrucous, scaly, often crusted papule or plaque. Biopsy is diagnostic.
  • Seborrheic keratosis – A hyperpigmented, "stuck-on"-appearing plaque with horn cysts not confined to arms, chest, head, and neck; usually multiple. Biopsy will show pseudohorn cysts.
  • Common acquired nevus – A skin-colored to hyperpigmented macule or papule that is usually not scaly. Biopsy is diagnostic.
  • Melanoma – Usually presents with irregularities in pigmentation, colors, borders, and symmetry. Biopsy is diagnostic.

Best Tests

Subscription Required

Management Pearls

Subscription Required


Subscription Required


Subscription Required

Last Reviewed:08/12/2019
Last Updated:08/12/2019
Copyright © 2024 VisualDx®. All rights reserved.
Lichenoid keratosis
A medical illustration showing key findings of Lichenoid keratosis : Single skin lesion
Clinical image of Lichenoid keratosis - imageId=82272. Click to open in gallery.  caption: 'A close-up of a pink-brown, edematous, stuck-on, verrucous plaque.'
A close-up of a pink-brown, edematous, stuck-on, verrucous plaque.
Copyright © 2024 VisualDx®. All rights reserved.