Safety and therapeutic effectiveness of 8-methoxypsoralen, 4,5',8-trimethylpsoralen, and psoralen in vitiligo.

In this paper, we report on 366 East Indian patients with vitiligo who were treated for 2 to 3 years with either 8-methoxypsoralen (8-MOP), 4,5',8-trimethylpsoralen (TMP), or psoralen and sunlight. These patients with amelanotic macules had 10 to 70% skin involvement of 1 to 50 years duration. Male and female patients from ages 12 to 70 years were randomly assigned to 8 treatment groups; the study was conducted on a double-blind protocol. Patients in prone and supine positions were exposed to the sun for 45-60 minutes in gradually increasing doses between 11 a.m. and 2 p.m. thrice weekly and 2 hours after oral ingestion of the drug. The various drug dosage schedules investigated included 9 groups: 0.3 and 0.6 mg 8-MOP/kg; 0.8, 1.8, and 3.6 mg TMP/kg; a combination of 0.3 mg 8-MOP and 0.6 mg TMP/kg; 0.6 and 1.2 mg psoralen/kg, and a placebo. For ethical reasons, the placebo group was terminated after 9 to 12 months of therapy. All patients were photographed before enrollment and at intervals of 6, 12, 18, and 26 months during therapy. Of these patients treated for nearly 2 years, the faces of those 45% receiving the combination dose of 8-MOP plus TMP or low-dose 8-MOP (0.3 mg/kg) were fully repigmented, and nearly 60% achieved 75 to 100% repigmentation of the head and neck. The chest, abdomen, and back were repigmented nearly as well and better than the arms and legs. The patients receiving high-dose schedules of TMP and psoralen achieved better repigmentation response than those on lower dosage but still not as good as patients on 8-MOP or the combination group of 8-MOP plus TMP.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronic cutaneous effects of long-term psoralen and ultraviolet radiation therapy in patients with vitiligo.

Vitiligo is refractory to most therapeutic modalities. To assess the efficacy of a variety of PUVA therapies, we enrolled 596 subjects in a prospective study, and 230 were followed for up to 55 months. Various psoralen derivatives and dosage schedules were used. Each subject was examined at yearly intervals for therapeutic response and evidence of chronic PUVA toxicity. At 4 years after therapeutic inception, 29 (13%) developed lesions in remaining vitiliginous macules. Clinically, hyperkeratotic macules and hyperkeratotic, lichenoid, and telangiectatic papules were discerned. Histologic examination of these lesions revealed them to be actinic and lichenoid keratoses, verruca vulgaris, and hyperkeratosis with either hyperplasia or atrophy. No tumors were present. In perilesional skin, dermal collagen and elastic tissue degeneration, much greater in degree than reported in psoriatic skin, was observed. In this group of PUVA-treated patients, no increased risk of carcinoma was apparent during the follow-up period.

Corneal and conjunctival effects of monobenzone in patients with vitiligo.

Monobenzone (the monobenzyl ether of hydroquinone [Benoquin]) is used topically by patients with extensive vitiligo to depigment their remaining normally pigmented skin. A patient who had been applying the drug for one year had an anterior linear deposition of pigment in both corneas. Of 15 additional patients with vitiligo, 11 of whom were using monobenzone, acquired conjunctival melanosis in two patients and pingueculae in three may have been related to monobenzone use. Light and electron microscopy of one corneal epithelial scraping and 12 conjunctival biopsy specimens revealed pleomorphic, single-membrane-limited intracytoplasmic inclusions within the corneal epithelium and within the epithelium, fibrocytes, histiocytes, and vascular endothelium of the conjunctiva. The ultrastructural aspects of these inclusions suggested that they are residual bodies containing lipid and lipofuscin.

Monobenzylether of hydroquinone. A retrospective study of treatment of 18 vitiligo patients and a review of the literature.

Of 18 severely afffected vitiligo patients who used 20% monobenzylether of hydroquinone (MBEH, Benoquin) as a depigmenting agent, 8 achieved complete depigmentation after 10 months or more of use and 3 dramatic but no complete hypopigmentation. The 3 patients with no results did not use MBEH for more than 4 months. Complications were frequent particularly among those who did well, but only 1 case of contact dermatitis limited therapy. All patients who depigmented fully were very pleased with their results. As depigmentation induced by MBEH is generally irreversible, MBEH use must be reserved for induction of complete depigmentation of severely affected vitiligo patients who cannot or do not choose to repigment and who can accept the permanence of never tanning. The history, histology and mechanism of MBEH depigmentation are discussed.