Oral lichen planus: an unusual cause of facial and abducens nerve paralysis associated with conjunctival and oesophageal involvement

Lichen planus (LP) is a T-cell-mediated disorder that may involve the skin, nails and mucosal surfaces. Conjunctival, laryngeal and oesophageal involvement were reported to be extremely rare manifestations of the disease. In this report, we present an oral LP case who complained of severe burning pain on his tongue and oral mucosa caused by ulcerative lesions and associated with conjunctival, laryngeal and oesophageal involvement. In addition, neurological examination revealed facial and abducens nerve palsy. To the best of our knowledge, we are presenting the first case of erosive oral LP associated with facial and abducens nerve paralysis. Although this association may be coincidental, according to an immunological concept proposed to explain the pathogenesis of Bell's palsy, degranulation of mast cells activated by complement or specific allergens with the release of histamine and other substances were to be presented responsible from nerve oedema, ischaemia and paralysis. As mast cell mediators are likely to be involved in the immunopathogenesis of OLP, we think that the cause of facial and bilateral abducens nerve palsy could be explained by the same mechanism. This case is a good example of the need for team work in lichen planus patients undergoing interdisciplinary consultations.