Particularly on the flexors of the wrists and forearms, on the lateral ankles, sharply demarcated, erythematous, lichenoid, polygonal, lacquer-like shiny, partly confluent papules and plaques appear. Often a whitish reticulation (wickham's pattern) can be seen. A characteristic feature of cutaneous primary efflorescences is the surface reflection, which is best recognised when the light is incident from the side. Exanthematous spreading may occur in the course. As a rule, the efflorescences flatten out again after months. Hyperpigmentation develops especially in dark-skinned patients.
- Wickham's drawing/ Wickham's phenomenon/ Wickham's stiffening: whitish reticulation on the primary efflorescences. This is often particularly visible around the mucous membranes. In patients with dark skin colour, the Wickham's pattern is often absent
- Köbner phenomenon: isomorphic stimulus effect triggered by mechanical, thermal or chemical triggers, which triggers a linear arrangement of primary efflorescences. This arises from manipulating / scratching the patient due to the lesional pruritus.
- Palmoplantar as well as lateral edges: Hyperkeratotic, whitish-yellowish plaques with erythematous margins may be visible.
- Nails:
- Rarely isolated infestation
- Dystrophy, atrophy, spotted nails, longitudinal striations (erythronychia), pterygia, subungual keratoses, onychoschisis
- Partial or complete destruction of the nail possible
- Capillitium:
- Lichen planus follicularis capillitii
- Pruritic, chronically stationary rather blurred, sometimes hyperkeratotic erythema. Sometimes tufts of hair are seen. Characteristic is the scarring arising from the erythema.
- Lichen planopillaris
- Diffuse disseminated follicular-bound erythema, which changes to hyperkeratotic papules up to 1 cm in diameter. In the course, these lesions may also become atrophic or scarring.
- A keratosis follicularis is partly visible on the upper arms or thighs
- Ulerythema ophryogenes is a follicular hyperkeratosis and vasodilatation of the eyebrows. In the course, follicular atrophy may occur
- Mucosal involvement (lichen planus mucosae): Wickham's stiffening is usually clearly visible here. In addition, whitish, nummular papules and plaques may also be visible
- In erosive lichen planus mucosae, there is an increased tendency to malignancy
- Lichen planus vulvae is characterised by an anular or circular form
