Retinoids and proliferative verrucous leukoplakia (PVL). A preliminary study.

OBJECTIVE A study is made of the efficacy and adverse effects of retinoid therapy applied to the white lesions of proliferative verrucous leukoplakia (PVL). MATERIAL AND METHODS The results of retinoid therapy were evaluated in 17 patients diagnosed with PVL. Topical retinoids were used in 5 patients, in the form of two daily applications of 0.1% 13-cis-retinoic acid in orabase for an average of 6.17+/-3.13 months. Systemic retinoids were used in 11 patients, with the administration of 25 mg/day of acitretin in tablet form for an average of 5.41+/-2.02 months. One patient successively received the topical and systemic retinoid formulations. The course and results were evaluated on a blind basis by two investigators. The adverse effects of the medication were also assessed. RESULTS Clinical improvement was recorded for 7 lesions (38.8%) (six involving systemic treatment and one as a result of topical application). Clinical worsening was recorded in the same proportion (5 lesions with systemic therapy and two with topical treatment), while four lesions (22.4%) showed no changes (one lesion with systemic therapy and three with topical treatment). Adverse effects were documented in all the patients administered the systemic formulation, versus in only one patient administered topical retinoids. The most frequent problems were desquamation and pruritus. CONCLUSION Although topical or systemic retinoic acid produces some improvement in about one-third of all patients with PVL, further studies are needed to assess the efficacy and safety of these products, in view of the important percentage of individuals who worsen despite therapy, and the frequent appearance of adverse effects.