Oral lichenoid drug eruptions

OBJECTIVES: To identify, from amongst drugs reported as causing lichenoid drug eruptions, those affecting the oral mucous membranes and to review the clinical, histo‐logical and immunological features of such oral lichenoid drug eruptions in comparison to oral lichen planus, amalgam contact lesions and lichen planus‐like eruption in graft‐versus‐host disease (GVHD). DATA SOURCES: Ovid® Medline data searches on CD‐Rom were carried out for the years 1966–1996 to identify reports of oral lichenoid drug eruptions and their clinical, histological and immunological featureS. Articles retrieved were examined for further appropriate references in the period 1940–1996. DATA EXTRACTION AND SYNTHESIS: Each paper was critically examined for evidence of a clinically verifiable lichenoid drug eruption affecting the oral mucous membranes and the effects of subsequent drug withdrawal. Available clinical, histological and immunological features were recorded. The papers examined were too diverse in nature to permit a structured criticism. The extracted data have been tabulated where appropriate. CONCLUSIONS: 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.