[Lichenoid drug reactions]

Lichenoid drug reactions are rare compared to typical morbilliform drug exanthema or urticaria. They are associated with specific drugs or drug families like gold, antimalarial drugs, β‑blockers and angiotensin-converting-enzyme inhibitors. Recent observations included associations with novel drugs such as biologics (e. g. tumour necrosis factor antagonists) and immune checkpoint inhibitors (anti-programme cell death protein 1 antibodies). Lichenoid drug reactions most often resemble lichen planus mainly in areas of ultraviolet-light exposed skin, but also mucosal lichen planus and even bullous lesions may occur.