Long-term efficacy of surgical removal of pseudomembranes in a child with ligneous conjunctivitis treated with plasminogen eyedrops

L igneous conjunctivitis (LC) was described as a pseudomembranous conjunctivitis for the first time in 1847. It is characterized by pseudomembranes with a woody consistency. So far, even more patients have been diagnosed with LC, and the involvement of tracheobronchial, mouth and female genital mucosal areas has been reported as well. Moreover, in some reports hydrocephalus and Dandy-Walker malformation have been described in association with LC. Histological examination of pseudomembranes shows a massive deposition of fibrin and amorphous hyalin-like eosinophilic material, accompanied by an inflammatory cellular infiltration. Fibrin deposition increases vascular permeability, influences the expression of inflammatory mediators and alters the migration and proliferation of various cell types (1). Plasminogen has been proposed to play an important role in inflammation and tissue remodelling processes (2). Mingers et al. (3) discovered the correlation between LC and plasminogen (PLG) deficiency. Inherited PLG deficiency in humans can be divided into two types: true PLG deficiency (type I) and dysplasminogenemia (type II); genetic mutations on plasminogen gene have been identified both in homozygous state and in compound heterozygous state (4). LC induced by type 1 PLG deficiency isasevere inflammation threatening visual function when affecting the cornea. It is characterized by woody pseudomembranes growing into the conjunctiva, mucus discharge and corneal scars. Patients complain of photophobia, itching and burning sensations. At the beginning, pseudomembranes can be easily removed; however, during the last phases of inflammation surgery can provide onlyaslight improvement because of the deep mucosal disorganization with the epithelium completely replaced by the pseudomembranes. Before knowledge the association between LC and plasminogen deficiency, patients were treated with topical corticosteroid, cyclosporineA, mytomicine and other anti-inflammatory agents without significant results. In the last few years treatment with topical plasminogen or fresh frozen plasma has been applied experimentally in few patients with encouraging results.