Dan K. Chalker

A comparison of the efficacy and safety of adapalene gel 0.1% and tretinoin gel 0.025% in the treatment of acne vulgaris: A multicenter trial

BACKGROUNDnAdapalene is a new synthetic retinoid analogue developed for the topical treatment of acne vulgaris.nnnOBJECTIVEnThe study was designed to compare the efficacy and safety and adapalene gel 0.1% with tretinoin gel 0.025% in the treatment of grade II to II facial acne vulgaris.nnnMETHODSnThree hundred twenty-three patients were enrolled in this investigator-masked, randomized, parallel group, multicenter trial. Patients applied the test materials to the entire facial area daily, for a period of 12 weeks. Efficacy and cutaneous tolerance were assessed at baseline and weeks 2,4,8, and 12. Efficacy was determined by investigator counts of noninflammatory open and closed comedones, and inflammatory papules and pustules, as well as global improvement. Cutaneous tolerance was evaluated by erythema, scaling, and dryness, along with burning and pruritus.nnnRESULTSnStaring at weeks 2 and 4, adapalene gel produced numerically greater lesion reductions than did tretinoin gel for all lesion types. At week 12, the mean percent reduction in the different lesion counts was as follow: 49% versus 37% for total lesions (p<0.01); 46% versus 33% for noninflammatory lesions (p=0.02); 48% versus 38% for inflammatory lesions (p=0.06) in adapalene and tretinoin gel treatment groups, respectively. Cutaneous side effects were limited to a mild retinoid dermatitis occurring in both treatment groups; however, patients treated with adapalene gel tolerated this therapy significantly better than those treated with tretinoin gel. Laboratory test evaluations (hematology, blood chemistries, urinalysis) were performed in 54 patients before and after 3 months of treatment. No clinically significant changes were observed.nnnCONCLUSIONnAdapalene gel 0.1% applied once daily was significantly more effective in reducing acne lesions and was better tolerated than tretinoin gel 0.025% in the treatment of acne vulgaris.

A double-blind study of the effectiveness of a 3% erythromycin and 5% benzoyl peroxide combination in the treatment of acne vulgaris

One hundred sixty-five subjects completed a 10-week, double-blind controlled study comparing the following: (1) a combination of 3% erythromycin and 5% benzoyl peroxide in a gel, (2) 5% benzoyl peroxide gel, (3) 3% erythromycin gel, and (4) the gel vehicle. The benzoyl peroxide gel and the erythromycin gel were superior to the control gel; however, the combination product was more effective than any of the others. This was true for both pustular and papular lesions, but the most dramatic effect was on combined inflammatory lesions, i.e., papules and pustules.

Topical erythromycin with zinc in acne: A double-blind controlled study

This double-blind controlled study investigated the effectiveness of 4% topical erythromycin liquid with 1.2% zinc acetate and 4% topical erythromycin gel with 1.2% zinc octoate applied twice daily in comparison with 250 mg of oral tetracycline twice daily and placebo. One hundred forty-nine patients began and one hundred forty-one completed the study. Three judges recorded acne measurements of severity grade, papule counts, pustule counts, comedo grades, and comedo counts without mutual consultation on visits at 0, 2, 4, 6, 8, and 10 weeks. Analysis of the reduction in the acne severity grade and papule count showed that the erythromycin/zinc liquid and gel were statistically significantly better than placebo and as effective as the oral tetracycline. Analysis of comedo grades showed that at weeks 8 and 10 the 4% topical erythromycin/zinc liquid showed a reduction statistically better than placebo.

An evaluation of a 2% erythromycin ointment in the topical therapy of acne vulgaris

Two hundred eight patients completed a 12-week, multicenter, double-blind, controlled study comparing a 2% erythromycin ointment to its vehicle. Patients were evaluated by inflammatory lesion counts and Cook acne severity grade at the initial visit and at weeks 2, 4, 8, 10, and 12. The 2% erythromycin ointment proved to be statistically more effective than the vehicle in reducing lesion counts and acne severity grade at weeks 4, 8, 10, and 12. The ointment caused few side effects and was well tolerated by most patients.

Mitotic and Labelling Activity In Normal Human Epidermis In Vivo

Labelling and mitotic indices were studied in the epidermis of twenty‐eight young men. A mean labelling index of 5.5% was found from the whole study and a mean mitotic index of 0.06%. Mitotic index particularly was extremely variable; indices between 0.002 and 0.438% were found in individual biopsies. In the first two of three experiments in which mitotic index at 09.00 hours was compared with that at 15.00 hours, significant differences were found (15.00 hours > 09.00 hours by a factor of 2.6, P < 0.001). However, in the third such experiment no such difference was found, suggesting that the timing and occurrence of diurnal rhythms of mitotic activity may not be consistent in normal human epidermis. In the one experiment in which it was investigated, a significantly higher mitotic index was found at 21.00 hours compared to 09.00 and 15.00 hours. Labelling index did not vary significantly at 09.00, 15.00 or 21.00 hours. However, labelling index did show a significant pattern of change over a 12‐month period in two groups of subjects; peaks of labelling were seen in July and troughs in January. Very high ratios of labelled: mitotic cells were found, the median ratio for the whole study being ninety‐eight labelled: one mitotic cell. This finding supports the possibility that not all labelled cells subsequently go on to divide in normal human epidermis.

Serologic survey for markers of hepatitis B infection in dermatologists

A serologic survey for markers of hepatitis B virus (HBV) infection was conducted in 593 dermatologists. Serologic evidence for previous infection was found in 15.4%, indicating that dermatologists are an at-risk population comparable to many other specialties of medicine. Dermatologists with a history of blood transfusion, tattoo, and homosexuality had an increased prevalence of serologic markers for HBV. The type of practice, extent of surgery, and glove-wearing practices did not correlate with HBV serologic markers.

An attempt to use vincristine and colcemid to measure proliferative rates in normal human epidermis in vivo

A range of doses of vincristine (0.5–10 μg) or colcemid (5–100 μg) injected intradermally into normal volunteers failed to yield any significant accumulation of arrested mitoses. This was despite an apparently successful block of cells in metaphase by the highest three doses of each drug. Possible reasons for the failure to see accumulation are discussed. The results suggest that normal human epidermis is not a suitable system for application of the metaphase‐arrest technique using intradermal injection.