Lichenoid keratosis, lichen planus-like keratosis

Last Updated: 2022-12-28

Author(s): Navarini A., Anzengruber Florian.

ICD11: -

Benign lichenoid keratosis, solitary lichen ruber planus, lichen planus-like keratosis, involuting lichenoid plaque

Inflamed lentigo solaris or seborrhoeic keratosis with lichenoid infiltrate and reactive keratosis.

Occurs from the age of 30 in pigment-poor patients, more likely in women than men.

Lichenoid keratosis is an inflamed lentigo solaris or seborrhoeic keratosis. The reason for the inflammation can be trauma, dermatitis or sun exposure.

It is a small, solitary (in >90%), inflamed plaque or macula. The pigmentation and surface corresponds to the underlying lesion, i.e. flat to warty. Multiple, eruptive lichenoid keratoses may also develop at actinic sites. The colour is reddish-brown and then changes to grey-brown at involution.

Clinical, dermatoscopic, histological.

Trunk, distal arms, sometimes head and neck.

Dermoscopically, there are uniform clusters of grey dots, together with the signs of the preexisting lesion (seborrhoeic keratosis or lentigo). With time until spontaneous resolution, the typical dermatoscopic aspects are lost.

Sun protection, no other options.

Very good, it typically comes to spontaneous resolution after several months.

  • Shave excision (with histological examination)
  • Cryotherapy also possible in the absence of suspicion of other differential diagnoses
  • When multiple eruptive lichenoid keratoses occur, treatment with acitretin is possible