Proper application consists of placing a "fingertip unit" of medication at each of 10 spots on the face — two on the mid-forehead (left and right), one each on the tip of the nose and chin, two spaced across each cheek, and one on each side of thelower face at a location that is approximately mid-distance between the spots on the cheek.
Dr. Del Rosso is a clinical assistant professor of dermatology, University of Nevada School of Medicine, Las Vegas. He describes a series of studies he conducted that established the efficacy of his recommended application technique for achieving full, confluent coverage of the face, its success in treating acne patients, and the potential for patients to misapply their topical acne medication if they are not appropriately instructed.
"Educating patients about topical medication application is a critical component in the successful management of acne. Proper application technique underlies treatment efficacy and avoids overuse that can increase cost and adverse events. In addition, it standardizes the amount of medication used and allows the practitioner to judge how much medication to prescribe, thereby enabling compliance monitoring and control of the patient's need to return for professional follow-up," Dr. Del Rosso explains.
The application method he recommends involves placing a "fingertip unit" of medication at each of 10 spots on the face - two on the mid-forehead (left and right), one each on the tip of the nose and chin, two spaced across each cheek, and one on each side of the lower face at a location that is approximately mid-distance between the spots on the cheek. The actual fingertip unit is defined by the distal pulp region of the finger. After all of the dots of medication are applied, they are spread evenly to cover the entire face.
The efficacy of this technique for achieving full and uniform coverage was demonstrated in a study in which subjects used it to apply four different vehicles - a water-based gel, a viscous cream, a cream dispensed from a tube, and a lotion contained in a bottle - each of which was mixed with fluorescein dye.
"Illumination of the face with a Wood's light confirmed that the topical agent was adequately and evenly distributed over the forehead, temples, cheeks, nose and chin," using this method, Dr. Del Rosso reports.
After determining the quantity of medication that would be applied using this technique, Dr. Del Rosso demonstrated the potential for misuse in patients who are not given specific instructions for topical medication application.
Twenty patients with untreated acne were watched while they applied benzoyl peroxide-clindamycin gel from a sample tube. Seven patients (35 percent) spot-treated their lesions only, while three (15 percent) coated their faces twice.
"On average, patients using the spot treatment technique applied only about half the quantity of medication they would have if the recommended application method was used," Dr. Del Rosso observes.
Participants in that study were then instructed in the fingertip unit application technique. Quantity usage after 30 days was assessed by subtracting the weight of the returned medication tube from the baseline value. The patients were found on average to have used the expected quantity of the water-based gel. The effectiveness of that method was confirmed by analyses of inflammatory lesion counts, which were reduced by nearly two-thirds from the baseline mean of 13.5.
Dr. Del Rosso also investigated the impact of vehicle characteristics and product container on quantity used in a study in which 10 patients applied different vehicles from different types of containers over consecutive seven-day periods. Quantity used varied somewhat between vehicles and depending on the container, but in general it was estimated that a 45 gm quantity of gel or cream used once daily should last for approximately two months.
Disclosures: Dr. Del Rosso received an educational grant from Stiefel Laboratories to support his poster at the Summer Meeting of the American Academy of Dermatology. He serves as a consultant, investigator and/or speaker for a number of pharmaceutical companies, including Stiefel, Galderma, Medicis and Allergan, that market topical medications for acne.