tretinoin and kojic-acid

Postinflammatory hyperpigmentation (PIH) has posed a substantial challenge for patients with higher Fitzpatrick skin types, specifically types III to VI. Treatment modalities pose a number of limitations due to the number of treatments required, potential side effects, and overall efficacy. Fortunately, multiple therapies have been delineated that can be moderately to highly efficacious in treating PIH in patients with skin of color. This article will review some of these modalities and procedures for this common patient concern.

Topics: Chemexfoliation; Dermatitis; Dermatologic Agents; Dicarboxylic Acids; Drug Combinations; Ethanol; Glycolates; Humans; Hydroquinones; Hyperpigmentation; Inflammation; Keratolytic Agents; Lactic Acid; Pyrones; Resorcinols; Salicylates; Salicylic Acid; Skin Pigmentation; Tretinoin

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.

Topics: Administration, Topical; Asian People; Chemexfoliation; Dicarboxylic Acids; Drug Therapy, Combination; Glycolates; Glycyrrhiza; Humans; Hydroquinones; Low-Level Light Therapy; Melanins; Melanosis; Monophenol Monooxygenase; Phototherapy; Phytotherapy; Plant Extracts; Pyrones; Sunscreening Agents; Treatment Outcome; Tretinoin; Ultraviolet Rays

Melasma is an irregular brown or grayish-brown facial hypermelanosis, often affecting women, especially those living in areas of intense UV radiation. The precise cause of melasma remains unknown; however, there are many possible contributing factors. Because of its dermal component and tendency to relapse, melasma is often difficult to treat. The use of broad-spectrum (UVA + UVB) sunscreen is important, as is topical hydroquinone, the most common treatment for melasma. Other lightening agents include retinoic acid (tretinoin) and azelaic acid. Combination therapies such as hydroquinone, tretinoin, and corticosteroids have been used in the treatment of melasma, and are thought to increase efficacy as compared with monotherapy. Kojic acid, isopropylcatechol, N-acetyl-4-cysteaminylphenol, and flavonoid extracts are other compounds that have been investigated for their ability to produce hypopigmentation, but their efficacy, safety, or trial design indicates that the interventions would need further study before they could be recommended. Chemical peels, laser treatments, and intense pulsed light therapy are additional therapeutic modalities that have been used to treat melasma.

Topics: Adrenal Cortex Hormones; Adult; Chemexfoliation; Clinical Trials as Topic; Combined Modality Therapy; Dermabrasion; Dicarboxylic Acids; Double-Blind Method; Drug Therapy, Combination; Female; Flavonoids; Gonadal Steroid Hormones; Humans; Hydroquinones; Laser Coagulation; Melanosis; Phototherapy; Plant Extracts; Pregnancy; Pregnancy Complications; Pyrones; Randomized Controlled Trials as Topic; Skin; Sunlight; Treatment Outcome; Tretinoin; Ultraviolet Rays

Pigmentary disorders are one of the most common skin disorders among people of color. Dyspigmentation in the form of either hyperpigmentation or hypopigmentation is often psychologically devastating to patients with darker skin. There is marked contrast between normally pigmented hyperpigmented, hypopigmented or depigmented skin in people of color. Despite being common, pigmentary disorders remain difficult to treat.

Topics: Administration, Cutaneous; Arbutin; Black People; Dicarboxylic Acids; Humans; Hydroquinones; Keratolytic Agents; Pigmentation Disorders; Pyrones; Tretinoin

Tyrosinase is involved in the synthesis of melanin in the skin and hair as well as neuromelanin in the brain. This rate limiting enzyme catalyzes two critical steps (reactions) in melanogenesis; the hydroxylation of tyrosine to form DOPA and the subsequent oxidation of DOPA into dopaquinone. Several new aminophenol derivatives have been synthesized based on structure-activity relationship studies of N-(4-hydroxyphenyl)retinamide (1), a derivative of retinoic acid. In order to find new tyrosinase inhibitors, we investigated the effects of these p-aminophenols, including p-decylaminophenol (3), on the activity of mushroom tyrosinase. Compound 3 was the most potent agent, showing significant inhibition as compared with control. The inhibitory effects of 3 on tyrosinase activities were greater than seen with kojic acid, a well-known potent inhibitor of tyrosinase activity, which also causes adverse effects, including rash and dermatitis. A Lineweaver-Burk kinetic analysis of inhibition showed that 3 suppresses tyrosinase activity in a non-competitive fashion for both substrates, tyrosine and DOPA. These results suggest that 3 might be a useful alternative to kojic acid as a tyrosinase inhibitor.

Topics: Agaricales; Aminophenols; Enzyme Inhibitors; Kinetics; Monophenol Monooxygenase; Protein Binding; Pyrones; Structure-Activity Relationship; Tretinoin

Melasma (cloasma) is a typical hypermelanosis and a common dermatologic skin disease that involves sun-exposed areas of the skin. It mostly affects women of reproductive age. Solar and ultraviolet exposure are the most crucial etiologic factors. Pregnancy, certain endocrine disorders and hormonal treatments, cosmetics, phototoxic drugs, and antiseizure medications are well-known inducing and exacerbating factors. A classification of melasma is based on Wood's light examination, classifying it in four major clinical types and patterns: epidermal, dermal, mixed, and indeterminate. Different treatment options are currently available for melasma. The choice of proper treatment should take into account the type of melasma to be treated, the skin complexion of the patient, possible previous treatments, the expectations and compliance of the patient, and the season in which the treatment is started.

Topics: Chemexfoliation; Cosmetics; Dermatologic Agents; Dicarboxylic Acids; Drug Combinations; Humans; Hydroquinones; Hydroxybenzoates; Laser Therapy; Melanosis; Pyrones; Tretinoin

Several reports have demonstrated that exposure to ultraviolet light elicits increased pigmentation in the skin of the Skh:HR2 mouse. We have reexamined this model to assess its potential as a screen for compounds with skin-depigmenting activity. The application of the previously reported ultraviolet light-B (UVB) doses led to marked necrotic damage to the skin which greatly diminished the usefulness of the model for drug testing. We have modified this model by exposing the mice to a progressively increasing dose of UVB that promotes pigmentation with a marked reduction of skin irritation. Furthermore, for compound evaluation, we preselected only those mice which developed signs of increased pigmentation after the first week of UVB exposure. This was critical for any meaningful compound evaluation, since only about 50% of the mice eventually showed signs of increased pigmentation with UVB. Our modifications make it possible to use this model for evaluating new compounds with skin-depigmenting activity. The validity of this method has been examined with a number of compounds including hydroquinone, 4-hydroxyanisole, kojic acid and all-trans retinoic acid, all with known depigmenting activity.

Topics: Animals; Anisoles; Female; Hydroquinones; Mice; Mice, Hairless; Pyrones; Skin; Skin Pigmentation; Tretinoin; Ultraviolet Rays