Hydroquinone and Psoralens in the Therapy of Hypermelanosis and Vitiligo

Fitzpatrick, Thomas B.; Arndt, Kenneth A.; El-Mofty, Anwar; Pathak, Madhu A.

doi:10.1001/archderm.1966.01600230093025

Cited by 114 publications

(27 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Not long afterward, hydroquinone became available as a topical agent in parts of the United States, where it was noted to induce skin lightening in humans. 12 Spencer 13 performed one of the first studies using hydroquinone at concentrations of 2%, 3%, and 5% applied twice daily for 3 months to the dorsal surface of the hands of white men with solar lentigines. The results revealed a dose-dependent decrease in pigmentation on clinical examination, with maximum improvement after 2 months of treatment and relapse once treatment was stopped.…”

Section: Topical Treatments: the Old And The Newmentioning

confidence: 99%

Melasma: A comprehensive update

Sheth

Pandya

2011

Journal of the American Academy of Dermatology

265

288

View full text Add to dashboard Cite

Several methods of treatment are available to patients with melasma. First-line therapy usually consists of topical compounds that affect the pigment production pathway, broad-spectrum photoprotection, and camouflage. Second-line therapy often consists of the addition of chemical peels, although these must be used cautiously in patients with darker skin. Laser and light therapies represent potentially promising options for patients who are refractory to other modalities, but also carry a significant risk of worsening the disease. A thorough understanding of the risks and benefits of various therapeutic options is crucial in selecting the best treatment.

show abstract

Section: Topical Treatments: the Old And The Newmentioning

confidence: 99%

Melasma: A comprehensive update

Sheth

Pandya

2011

Journal of the American Academy of Dermatology

265

288

View full text Add to dashboard Cite

show abstract

“…369 Intentional use of HQ formulations for skin lightening in humans began in the 1950s, following anecdotal reports from the southern U.S. of depigmentation occurring as a side effect of an HQ-containing preparation designed as a sunscreen. 370 Early controlled clinical studies suggested that daily dermal application of creams containing 1.5% or greater concentrations of HQ were effective in producing at least mild cosmetic skin depigmentation after approximately 1 month of use, [371][372][373][374] although some clinicians reported negative results for HQ in the absence of additional ancillary components. 375 The incidence of skin irritation and inflammation associated with this treatment appeared to increase substantially with HQ concentrations above 2 to 3%.…”

Section: Dermal Effectsmentioning

confidence: 99%

The Toxicology of Hydroquinone — Relevance to Occupational and Environmental Exposure

DeCaprio¹

1999

Critical Reviews in Toxicology

178

128

View full text Add to dashboard Cite

Hydroquinone (HQ) is a high-volume commodity chemical used as a reducing agent, antioxidant, polymerization inhibitor, and chemical intermediate. It is also used in over-the-counter (OTC) drugs as an ingredient in skin lighteners and is a natural ingredient in many plant-derived products, including vegetables, fruits, grains, coffee, tea, beer, and wine. While there are few reports of adverse health effects associated with the production and use of HQ, a great deal of research has been conducted with HQ because it is a metabolite of benzene. Physicochemical differences between HQ and benzene play a significant role in altering the pharmacokinetics of directly administered when compared with benzene-derived HQ. HQ is only weakly positive in in vivo chromosomal assays when expected human exposure routes are used. Chromosomal effects are increased significantly when parenteral or in vitro assays are used. In cancer bioassays, HQ has reproducibly produced renal adenomas in male F344 rats. The mechanism of tumorigenesis is unclear but probably involves a species-, strain-, and sex-specific interaction between renal tubule toxicity and an interaction with the chronic progressive nephropathy that is characteristic of aged male rats. Mouse liver tumors (adenomas) and mononuclear cell leukemia (female F344 rat) have also been reported following HQ exposure, but their significance is uncertain. Various tumor initiation/promotion assays with HQ have shown generally negative results. Epidemiological studies with HQ have demonstrated lower death rates and reduced cancer rates in production workers when compared with both general and employed referent populations. Parenteral administration of HQ is associated with changes in several hematopoietic and immunologic endpoints. This toxicity is more severe when combined with parenteral administration of phenol. It is likely that oxidation of HQ within the bone marrow compartment to the semiquinone or p-benzoquinone (BQ), followed by covalent macromolecular binding, is critical to these effects. Bone marrow and hematologic effects are generally not characteristic of HQ exposures in animal studies employing routes of exposure other than parenteral. Myelotoxicity is also not associated with human exposure to HQ. These differences are likely due to significant route-dependent toxicokinetic factors. Fetotoxicity (growth retardation) accompanies repeated administration of HQ at maternally toxic dose levels in animal studies. HQ exposure has not been associated with other reproductive and developmental effects using current USEPA test guidelines. The skin pigment lightening properties of HQ appear to be due to inhibition of melanocyte tyrosinase. Adverse effects associated with OTC use of HQ in FDA-regulated products have been limited to a small number of cases of exogenous ochronosis, although higher incidences of this syndrome have been reported with inappropriate use of unregulated OTC products containing higher HQ concentrations. The most serious human health effect related to HQ is p...

show abstract

“…Advantages to this regimen include: (1) a controlled stimulus, devoid of untoward reactions; (2) the use of weekly treatment schedules; (3) avoidance of systemic admin¬ istration of a drug; (4) no generalized hyperpigmentation; (5) inexpensive light source; and finally, (6) some discernible repigmentation in the majority of patients.…”

Section: Resultsmentioning

confidence: 99%