Cosmetic and dermatologic use of alpha hydroxy acids

Alpha hydroxy acids (AHAs), in particular glycolic acid, are a class of chemical compounds frequently used in cosmetics and dermatology. This review summarizes the current knowledge regarding chemistry, mechanism of action as well as the different indications ranging from cosmetic skin hydration to acne proven by clinical trials. Overall AHAs depending on the concentration used present an ingredient for cosmetic products or medical devices with proven efficacy.     

The use of hydroxy acids on the skin: characteristics of C8-lipohydroxy acid

The hydroxy acids are widely used in skin creams because of their exfoliating and rejuvenating effect on photoaged skin. As a member of this family, the salicylic acid derivative known in the literature as 2-hydroxy-5-octanoyl benzoic acid or beta-lipohydroxy acid has also been proposed as an exfoliant and as a treatment of photoaged skin and acne. This article reviews the effects of the hydroxy acids and compares them to those of the salicylic acid derivative. We propose the name C(8)-lipohydroxy acid (C8-LHA) for this derivative to differentiate it from other related compounds. The lipophilic nature of C8-LHA and its relatively slow penetration in the skin afford it an exfoliating effect that is efficient at low concentrations. It appears to have antimicrobial, anti-inflammatory, and anticomedogenic properties, which make it effective against acne. Its antifungal and exfoliating properties are also likely to prove useful in combating dandruff.     

Cutaneous inflammation: effects of hydroxy acids and eicosanoid pathway inhibitors on vascular permeability

Four metabolic products of arachidonic acid lipoxygenation, 5-hydroxyeicosatetraenoate (5-HETE), 12-HETE, 15-HETE, 5(S),12(S)-DiHETE, were injected intradermally into depilated dorsae of albino guinea pigs. The presence of intravenously injected 125I-bovine serum albumin (10uCi/kg) in 13-mm punch biopsy specimens served as a marker for altered vascular response; histologic changes were evaluated at 6 and 24 h after the injection in 1-micron-thick sections. Thirty minutes after the injections of 15 nanomoles and 60 nanomoles of 5-HETE, the ratios of radioactivity in HETE-injected to that in buffer-injected sites were 1.35 +/- 0.06 (mean +/- SE) and 2.80 +/- 0.27, respectively. Corresponding effects of 15-HETE were 1.39 +/- 0.17 and 1.63 +/- 0.21, respectively. Values for 60 nanomoles of 12-HETE and 5,12-DiHETE were intermediate in comparison with the above eicosanoids. The most notable histologic changes were a neutrophilic infiltrate induced by 12-HETE at 6 and 24 h, and neutrophilic and eosinophilic infiltrates in response to 5,12-DiHETE injection at 6 and 24 h. Effects of topically applied eicosanoid pathway inhibitors were also evaluated, using intradermally injected sodium arachidonate (AA) as agonist. Three mixed cyclooxygenase/lipoxygenase inhibitors, BW755C, phenidone, and nordihydroguaiaretic acid, suppressed vascular response by 9%, 9%, and 6% for 150 nmol of AA, and by 9%, 13%, and 12% for 300 nmol of AA, respectively. The cyclooxygenase inhibitor, indomethacin, induced suppressions of 39% for 150 nmol AA and 22% for 300 nmol AA, respectively. These data demonstrate that metabolites of both cyclooxygenase and lipoxygenase eicosanoid pathways are involved in alteration in vascular response accompanying cutaneous inflammation.     

Laser‐assisted drug delivery: mode of action and use in daily clinical practice

Topical application of pharmaceutical agents is a basic principle of dermatological therapy. However, the effective barrier function of the skin significantly impairs the bioavailability of most topical drugs. Fractional ablative lasers represent an innovative strategy to overcome the epidermal barrier in a standardized, contact‐free manner. The bioavailability of topical agents can be significantly enhanced using laser‐assisted drug delivery (LADD). In recent years, the principle of LADD has become well established for various dermatological indications. Herein, we review the current literature on LADD and present potential future applications.     

Psoriatic arthritis: clinical spectrum and diagnostic procedures

Psoriatic arthritis presents with a broad clinical spectrum of symptoms. Symmetrical polyarthritis with joint pain and joint swelling is one pattern of clinical manifestations that often indicates erosive progressive disease. Unlike in rheumatoid arthritis, the distal interphalangeal joints are regularly involved. Sometimes, the disease focuses on the larger joints of the lower extremities; iliosacral and intervertebral joints and tendons can also be involved. Thus, inflammatory back pain as well as any other prolonged joint pain in a patient with psoriasis is suspicious of psoriatic arthritis. This article reviews the clinical spectrum and diagnostic procedures that can lead to the diagnosis of psoriatic arthritis.     

Psychosomatic factors in dermatology: special perspectives for application in clinical practice

The identification of psychosomatic factors in dermatology has always been one of the principal themes in the history of this field and in the personal experience and research of the author. After a brief review of some of the milestones in the area of psychosomatic factors in dermatology, the author presents the criteria dictated by clinical experience, in the absence to date of more precise scientific data, for the individuation of such psychosomatic factors in clinical practice.     

Developing an international standard for the classification of surface anatomic location for use in clinical practice and epidemiologic research

1. Download : Download high-res image (305KB)
2. Download : Download full-size image

     

Tinea capitis: current concepts in clinical practice

Tinea capitis is a common infection, particularly among young children in urban regions. The infection often is seen in a form with mild scaling and little hair loss, a result of the prominence of Trichophyton tonsurans (the most frequent cause of tinea capitis in the United States). T. tonsurans does not fluoresce under Wood light, unlike the common tinea capitis-causing fungal organisms seen in Europe and many other countries, which emit a green fluorescence. However, T. tonsurans, like other fungi, also may less often produce an intense inflammatory reaction, which is suggestive of an acute bacterial infection.     

Dermatoscopy: alternative uses in daily clinical practice

Dermatoscopy, also known as dermoscopy, epiluminescence microscopy, or surface microscopy, is a noninvasive technique allowing rapid and magnified (× 10) in vivo observation of the skin with the visualization of morphologic features often imperceptible to the naked eye. Videodermatoscopy (VD) represents the evolution of dermatoscopy and is performed with a video camera equipped with lenses providing higher magnification (× 10 to × 1000). Over the past few years, both dermatoscopy and VD have been demonstrated to be useful in a wide variety of cutaneous disorders, including ectoparasitic infestations, cutaneous/mucosal infections, hair and nail abnormalities, psoriasis, and other dermatologic as well as cosmetologic conditions. Depending on the skin disorder, both dermatoscopy and VD may be useful for differential diagnosis, prognostic evaluation, and monitoring response to treatment. Nowadays, it represents an important and relatively simple aid in daily clinical practice.     

Optimising the use of tazarotene in clinical practice: consensus statement from the European advisory panel for tazarotene (Zorac TM).

BACKGROUND: This paper reports the proceedings of the European Advisory Panel Meeting for tazarotene (Zoractrade mark), which took place in Cologne on May 7, 1998. AIM: The aim of this meeting was to discuss recommendations for the use of tazarotene based on the clinical data available and on the clinical experience of the Advisory Panel members, and to identify future research needs. RECOMMENDATIONS: Based on currently available data, tazarotene can be used for the treatment of chronic, stable, plaque-type psoriasis, on the trunk or limbs covering up to 20% of the body surface area. In clinical trials, patients generally experienced a clinical response within 4 weeks of starting tazarotene treatment, and improvement was maintained for up to 12 weeks after stopping therapy. Results from published and not yet published clinical trials show that the efficacy and tolerability of tazarotene can be enhanced by the addition of topical corticosteroids to the treatment regimen and that, when used in combination with broad-band UVB phototherapy, tazarotene reduces the amount of UV light required to treat plaques. Tazarotene gel is available in two concentrations, 0.05 and 0.1%. The Advisory Panel recommends that the choice of concentration should be based on factors such as the irritability of the patient's skin and the thickness of plaques. Irritation can be managed by reducing the concentration or frequency of application, or by adding a topical corticosteroid to therapy. Tazarotene shows promise as a treatment for psoriasis in special localisations, such as the scalp, face and skin folds, although clinical studies are required.     

Latex allergy in clinical practice

A continuous exposure or contact to latex products may sensitize the human body by causing mild to fatal reactions. Despite the availability of the literature, medical personnel are still unaware of the implications of the use of latex materials. The increased awareness to prevent the transmission of infectious blood borne pathogens has lead to increased usage of medical gloves among health care workers. This increased usage of medical gloves, along with improved methods in diagnosing latex allergy, has been the reason for the rise in the number of reported cases. This has lead to recognition of latex allergy as a serious medical concern. Patients in high-risk groups must be assessed carefully, so that appropriate protocols can be used to protect them from contact with latex.