RESUMEN
This study aimed to assess the efficacy of low dose of low molecular weight [LMW] heparin as a monotherapy in lichen planus [LP] and to evaluate the MMP-9 in LP before and after treatment in a trial to study its role. Twenty patients with different clinical varieties of LP received 3 mg SC of LMW heparin/week for eight weeks. Five CC of blood were taken from ten healthy persons and from all patients before and after treatment. The expression of MMP9 was evaluated in tissues of LP patients before and after therapy. It was found that MMP-9 level in serum and its expression in the tissue of LP patients were significantly increased as compared with patients and controls after treatment suggesting that it may have an active role in the pathogenesis of LP. Also, it was found that LMW heparin may be an effective therapy in acute generalized LP