Drug lichenoid eruption

Lichen planus-like or lichenoid eruptions from certain drugs and compounds can closely mimic idiopathic lichen planus. The patient's history and physical examination histopathologic criteria, and certain tests can assist in the differentiation between a lichenoid drug eruption and idiopathic lichen planus and in the identification of the offending drug.

 

Lichenoid drug reactions are specific unwanted cutaneous side-effects related to some drugs. The clinical presentation of the lesions often suggests the diagnosis, but the distinction with idiopathic lichen planus remains difficult. The diagnosis is firmly established by the dermatopathological assessment of a cutaneous biopsy. The anamnestic search is focused on drug imputability based on well defined criteria. Biologic evaluations and various in vitro tests are little contributive and even may prove to be irrelevant.

 

 

The reports of oral lichenoid drug eruptions are considerably fewer than those of cutaneous eruptions and fewer drugs have been reported as causing oral rather than cutaneous lichenoid eruptions. Histology and immunology cannot be used reliably to differentiate lichenoid drug eruptions from idiopathic lichen planus, amalgam contact lesions and lichen planus-like eruption in GVHD. Lichenoid drug eruptions may also show some histological characteristics of oral discoid lupus erythematosus. An accepted protocol agreed by a number of international centres would permit the gathering of substantial information on LDE and could lead to a greater understanding of the mechanisms involved.