Treatment of postcryosurgery wounds with a trolamine/sodium alginate topical emulsion versus standard of care

Journal of Drugs in Dermatology, May, 2008 by Brad A. Yentzer, Rebekah Wilson, Mandeep Kaur, Adele Clark, Trudye Young, Lisa Williams, Steven R. Feldman, Phillip M. Williford, Rita Pichardo

Abstract

Background: Actinic keratoses are commonly treated with cryosurgery, often causing a wound that may blister and crust. Proper wound care aids in better healing and patient satisfaction.

Objective: To evaluate the use of a topical trolamine/sodium alginate emulsion (TAE) cream for actinic keratosis treatment wounds in the clinical setting.

Methods: Twenty subjects, 50 years of age or older, were enrolled in this investigator-blinded prospective study. Subjects were randomized to apply a topical TAE to wounds on 1 forearm and bacitracin/polymyxin B sulfate (BPB) (standard of care) to wounds on the other forearm. Medications were applied 3 times per day for 4 weeks to the areas treated with liquid nitrogen at baseline.

Results: Both the treatment and control groups displayed significant decreases in severity from baseline to week 4 for erythema, thickness, and mean severity scores. However, severity of the TAE-treated group decreased at a faster rate as evidenced by mean combined erythema, scab, and thickness scores of 1.20 compared to 1.58 for the BPB-treated group at week 2 (P <.01).

Conclusions: While wound treatment with both methods was effective and well tolerated, the trolamine emulsion helped postcryosurgery wounds heal somewhat more quickly. The utilization of nonantibiotic medication also may help curb the growing problem of bacterial resistance.

Introduction

Actinic keratoses (AKs) are typically treated with cryosurgery, leading to subsequent erythema, blistering, and crusting at the treatment site. Postcryosurgery wounds are the most common type of iatrogenic wound associated with dermatology, and the care of these wounds is a concern for patients and their physicians.

The optimal management of skin wounds includes keeping the area moist and protected.(1) Biafine[R] is a water-based, trolamine/sodium alginate emulsion (TAE) that provides a moist environment for the healing process. It has recently been introduced in the US and is marketed for the treatment of superficial wounds, minor abrasions, dermal ulcers, donor sites, first-degree and second-degree burns, and radiation dermatitis.(2) Topical emulsions containing trolamine have the ability to promote healing by recruiting increased numbers of macrophages to the wound site, thereby reducing wound healing time.(3) In human skin models maintained ex wo, a TAE increased epithelial cell proliferation and reduced dermal edema when tissues were exposed to radiation. (4)

Postcryosurgery wounds are generally treated with antibiotic ointments such as bacitracin zinc/polymyxin B sulfate (BPB; Polysporin[R]). The efficacy of topical antibiotics is questionable.' Solid clinical data on the safety and efficacy of a TAE in the treatment of postcryosurgery wounds are also lacking. The goal of this study was to compare a TAE to the standard of care (Polysporin) for wounds resulting from the treatment of AK lesions with cryosurgery.

Methods

A total of 20 male and female subjects, 50 years of age or older, were recruited after undergoing cryosurgical treatment of at least 1 AK on each forearm. Postcryosurgery target lesions were evaluated for wound healing according to assessments over time of lesion redness, thickness, crusting/scabbing, and overall severity on a 5-point scale (0=absent, l=slight, 2=mild, 3=moderate, 4=severe). To be included in this study, subjects had to have target lesions with a severity score of at least 1 in each category. Patients were excluded if they had a known allergy or sensitivity to the study medication, had received any other topical or systemic treatment to treat AK, or were using any other topical medications in the treatment area. Approval for this study was given by an institutional review board, and written informed consent was obtained from each subject.

Upon each subject's agreement to participate, target lesions on both arms were photographed and assessed and baseline severity scores were recorded. Subjects were then randomized to apply a TAE to the target lesions 3 times per day on 1 fore-arm and BPB ointment (standard of care) 3 times per day on the other forearm. The specific treatment area for each medication was demonstrated for the patients. Study medication was weighed and distributed, and patients were asked to follow-up at weeks 1, 2, and 4, and to bring their medication tubes at each visit.

At each follow-up visit, target lesions were assessed for wound healing progress using the same severity scale. Evaluators performing assessments were blinded with regard to the treatment assignment for each group. Patients were asked to report any adverse events while using the study medications, as well as any additional medications used during the study period.

The primary endpoint was to compare the efficacies of TAE and BPB for the treatment of wounds created by cryosurgery for AK lesions. The efficacy of the different study medications was assessed by comparing progress from baseline to week 4 Differences in baseline values between the TAE and BPB treatments, in addition to differences between the results at week 4 and baseline were tested by using standard paired t tests. For comparisons at other time points, mixed models were fitted to the data, with dependent variables defined as the difference between TAE and BPB severity scores at each follow-up visit. Independent variables included differences between baseline and the visit week.