RALGA (Diacnéal®), a Retinaldehyde and Glycolic Acid Association and Postinflammatory Hyperpigmentation in Acne – A Review

Postinflammatory hyperpigmentation: etiologic and therapeutic considerations

Postinflammatory hyperpigmentation (PIH) is a reactive hypermelanosis and sequela of a variety of inflammatory skin conditions. PIH can have a negative impact on a patient's quality of life, particularly for darker-skinned patients. Studies show that dyschromias, including PIH, are one of the most common presenting complaints of darker-skinned racial ethnic groups when visiting a dermatologist. This is likely due to an increased production or deposition of melanin into the epidermis or dermis by labile melanocytes. A variety of endogenous or exogenous inflammatory conditions can culminate in PIH and typically most epidermal lesions will appear tan, brown, or dark brown while dermal hypermelanosis has a blue-gray discoloration. Depigmenting agents target different steps in the production of melanin, most commonly inhibiting tyrosinase. These agents include hydroquinone, azelaic acid, kojic acid, arbutin, and certain licorice (glycyrrhiza) extracts. Other agents include retinoids, mequinol, ascorbic acid (vitamin C), niacinamide, N-acetyl glucosamine, and soy, and these products depigment by different mechanisms. Certain procedures can also be effective in the treatment of PIH including chemical peeling and laser therapy. It is important to note that these same therapeutic modalities may also play a role in causing PIH. Lastly, those lesions that are not amenable to medical or surgical therapy may experience some improvement with cosmetic camouflage.

Effective over-the-counter acne treatments

Acne is the most common disease of the skin, yet only a fraction of acne sufferers are treated with prescription products by physicians. There is, however, a large and expanding market for over-the-counter (OTC) medications, many of which are not only effective but also well tolerated and cosmetically elegant. Given the presence of OTC acne medications on the television, the Internet, and store shelves, patients will be acutely aware of these OTC remedies and will have questions. Patients will expect dermatologists to advise them regarding products to use either as a sole therapy or in combination with prescription drugs. Recently, combinations of OTC acne medications in treatment regimens or "kits" have gained popularity and appear to have increased patient compliance. Quality-of-life outcomes from OTC medication use, in at least one study, have demonstrated good benefit. The most common OTC ingredients include benzoyl peroxide, a potent antibacterial agent, and salicylic acid, a mild comedolytic and antiinflammatory medication. Other, less-common OTC ingredients include sulfur, sodium sulfacetamide, and alpha hydroxy acids. Zinc, vitamin A, tea tree oil, and ayurvedic therapies also are available OTC for acne. Additional and better studies are needed to clarify the benefit of these latter medications.

Combined 0.1% Retinaldehyde/ 6% Glycolic Acid Cream in Prophylaxis and Treatment of Acne Scarring

BACKGROUND

Acne often results in permanent, badly tolerated, difficult to treat scars.

OBJECTIVE

To evaluate the efficacy and safety of a 0.1% retinaldehyde/6% glycolic acid (RALGA) cream at preventing and treating acne scarring in patients previously treated for moderate acne.

METHODS

A double-blind vehicle-controlled study was conducted in 145 patients randomized to apply RALGAor vehicle cream every evening for 3 months. Global scarring score and patient's assessment of global efficacy, then residual acne lesions, quality of life and tolerance were evaluated at inclusion and each month until study completion.

RESULTS

Global scarring score, number of inflammatory lesions and comedones significantly improved in each group from day 28 (p<0.0001). Number of inflammatory lesions were significantly decreased only in the RALGA group. RALGA cream was more efficient than vehicle on scarring after 3 months in compliant patients (p=0.007) due to erythema and hyperpigmentation improvement.

CONCLUSION

RALGA cream is efficient at preventing and treating acne scarring in patients with moderate acne.

The safety of hydroquinone

Hydroquinone is one of the most effective molecules for the treatment of hyperpigmentary disorders, with over 40 years of efficacy and safety data. Concerns over its safety have been raised because of the fact that it is a derivative of benzene and because of the long-term side-effects observed with cosmetic products containing high concentrations of hydroquinone. However, despite 40-50 years use of hydroquinone for medical conditions, there has not been a single documented case of either a cutaneous or internal malignancy associated with this drug. This article reviews the evidence for the safety of hydroquinone in the treatment of hyperpigmentation conditions.

Update in retinoid therapy of acne

The pathogenesis of acne, the most common skin disease, is complex and multifactorial. Clinical experience has demonstrated that parallel targeting of various pathogenetic factors, achieved either by mono- or combination therapy with appropriate drugs, represents the most effective approach to treating acne. Topical retinoids have been shown to expulse mature comedones, reduce microcomedone formation, and exert immunomodulatory effects. They have broad anti-acne activity without the risk of inducing bacterial resistance, which justifies their use as first-line treatment in most types of noninflammatory and inflammatory acne and makes them uniquely suitable as long-term medication to maintain remission after cessation of initial combination therapy. Systemic isotretinoin as a monotherapeutic agent strongly affects all four major pathogenetic factors and has been, in the hand of experienced dermatologists, a potent and safe agent for the treatment of severe and recalcitrant acne forms for more that 20 years. However, patient counseling, careful monitoring, and evaluation and management of adverse events are necessary. The use of isotretinoin has experienced a drawback now that its indication has been lowered from a first-line to a second-line medication.