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Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


Lichenoid keratosis

What is lichenoid keratosis?

Lichenoid keratosis is usually a solitary lesion that looks similar to a lentigo, Bowen disease (in situ squamous cell carcinoma), or superficial basal cell carcinoma. Histopathology (the microscopic structure and changes of the lesion) resembles that of lichen planus with some slight differences. The lesions appear to develop from a regressing existing lesion such as a lentigo or seborrhoeic keratosis as on close examination remnants of these former lesions may be evident.

Lichenoid keratosis is also known as benign lichenoid keratosis, solitary lichen planus, lichen planus-like keratosis and involuting lichenoid plaque.

Lichenoid keratosis Lichenoid keratosis Lichenoid keratosis
Lichenoid keratoses

Who gets lichenoid keratosis?

Lichenoid keratosis is an uncommon lesion with most cases usually discovered by doctors performing careful skin examinations. Most lesions develop in patients aged between 30-80 years and affect females more than males by 2:1. The condition is most commonly seen in Caucasians and rarely affects Asians, African Americans or Hispanics.

What are the clinical features of lichenoid keratosis?

The clinical features of lichenoid keratosis vary somewhat in relation to their histopathological findings and how long they have been present. These attributes have been used to define several clinical subtypes of lichenoid keratosis.

Classic, bullous or atypical subtype
Clinical features
  • Acute rapidly developing lesion (present for <3 months)
  • Erythematous or pinkish papule or plaque
  • Dermoscopy may show remnants of pigment network, subtle blotches of brown colour, clusters of grey dots plus dotted, irregular linear and other shaped telangiectatic blood vessels
Histopathology
  • Classic variant shows epidermal acanthosis with a band-like lichenoid lymphocytic infiltrate. Presence of epidermal parakeratosis distinguishes these lesions from typical lichen planus.
  • Bullous variant shows intraepidermal or subepidermal bullous cavities with dense lymphocytic infiltrate and increased number of necrotic basilar layer keratinocytes.
  • Atypical variant shows similar histology to classic type with scattered enlarged CD-3, CD-30 (+) lymphocytes with hyperchromatic, irregular nuclei.
Early or interface subtype
Clinical features
  • Subacute lesions present for 3 months to one year
  • Erythematous to dusky-red or hyper-pigmented brown lesion
  • Depending on the age of lesion, dermoscopy may show features of a solar lentigo or flat seborrhoeic keratosis with moth-eaten borders, fingerprinting, milia-like cysts, comedo-like openings, plus small foci of melanophages (grey dots).
Histopathology
  • Single lymphocytes aligned along the dermoepidermal junction without epidermal acanthosis and adjacent lentigo
Late regressed or atrophic subtype
Clinical features
  • Lesions have been present for more than one year
  • May be violaceous (violet-coloured) papules or irregularly distributed lesions with shades of brown or grey
Histopathology
  • Epidermal atrophy with papillary dermal scarring, patchy lymphocytic infiltrates and melanin incontinence

Other features of lichenoid keratosis found in all subtypes are:

What is the management of lichenoid keratosis?

Initially the lesion is examined using dermoscopy. For lesions that are considered low-risk dermoscopic images can be taken and used in follow-up sessions over time to check for any significant changes.

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Dermoscopy of lichenoid keratoses

Because clinical examination and dermoscopy may not be able to differentiate between lichenoid keratosis and other solitary erythematous lesions that could be melanocytic, non-melanocytic benign, malignant or inflammatory, a skin biopsy may be necessary to confirm diagnosis of suspicious lesions. Complete excision rather than an incisional biopsy is recommended.

Once the diagnosis of lichenoid keratosis is confirmed, the patient should be advised about the benign nature of the lesion and offered medical or surgical treatment to remove any remaining lesion. This may be treatment with liquid nitrogen, electrosurgery or curettage. In some cases the remaining lesion can be left alone.

To date there have been no reports of lichenoid keratosis turning into malignant skin tumours.

Related information

References:

Lichen Planus-Like Keratosis. The Doctor's Doctor

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Author: Vanessa Ngan, staff writer

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If you have any concerns with your skin or its treatment, see a dermatologist for advice.