Cosmetic Benefits Improve Compliance in Dandruff/Seborrheic Dermatitis Shampoo Treatment
Zoe Diana Draelos, MD1; Dianna C. Kenneally, BS Ch.E2; Ward L. Billhimer, MS2; Megan Copas, BS2; Laura Lebda, BS2
1Department of Dermatology, Wake Forest University School of Medicine; 2The Procter & Gamble Company
Dandruff is a chronic scalp condition caused by sebum, Malassezia, and individual susceptibility1 with common symptoms being scaling, itching and irritation. Frequent shampooing with antidandruff product is key to controlling symptoms; however, many female patients are reluctant to routinely use antidandruff shampoo due to perceived loss of hair cosmetic benefits. The recognition that hair quality must be maintained while treating dandruff has led to the next generation of dandruff shampoos incorporating technologies for minimizing fungal colonization of the scalp and silicone-based conditioners to maximize hair beauty. This study evaluated a novel 1% pyrithione zinc conditioning shampoo as compared to a 2% ketoconazole shampoo in improving hair condition and subject compliance while effectively treating dandruff.
- Measure differences in hair quality between novel 1% PTZ conditioning antidandruff shampoo vs. 2% ketoconazole shampoo.
- Evaluate the impact of hair quality improvements on clinical participant satisfaction and willingness to continue to use antidandruff shampoo. Methods 40 females between the ages of 18-50 with mild to moderate dandruff were enrolled in this IRB approved four week double blind cross over study. Subjects had hair of sufficient length such that it could be combed. Subjects underwent a one week washout period with a basic non-conditioning cleansing shampoo to standardize hair condition. 20 randomized subjects received the novel conditioning 1% novel pyrithione zinc shampoo and the remaining 20 subjects received a 2% ketoconazole shampoo. At the end of one week, subjects crossed over to use the other study shampoo for an additional week. At the end of the second test week, subjects were asked to pick their preferred shampoo for continued use during the last two weeks of the study. Subject assessments and investigator assessments of scalp scale, crusting, erythema, and hair quality were collected at baseline, week 1, week 2, and week 4. All subjects completed the study with no adverse events.
Dandruff Efficacy Was Equal
While efficacy was not the primary focus of this investigation, it is important to note that both products controlled dandruff equally well in this study. Improvement in flaking and erythema were not statistically different between products, although a directional advantage for 1% PTZ shampoo was seen at Week 1 (p=0.1021). A statistical analysis for carry over effect was performed to confirm that the test design did not bias the efficacy result (p=0.40 for scaling, p=0.39 for erythema). As a result, the investigators believe efficacy did not drive preference differences in the study. 1% PTZ Conditioning Shampoo Improved Hair Quality The investigator measured significant improvements in hair quality resulting from the conditioning ingredients in the PTZ test shampoo. After one week of use, the PTZ shampoo was significantly better than the ketoconazole shampoo at improving hair smoothness (p=0.035) and hair combing (p=0.045) and directionally better for frizz/flyaway (p=0.289). During the second study week, the PTZ shampoo was also significantly better than the ketoconazole shampoo at improving hair frizz/flyaway (p=0.005) and hair smoothness (p=0.0004) and directionally better for ease of combing (0.201). Additionally, The study subjects were able to see significant improvements in hair quality resulting from the PTZ shampoo. An average of the panel self assessment ratings showed both ease of wet combing and conditioned hair feel (p<0.05) significantly higher for the PTZ shampoo. Hair Improvement Increased Willingness to Use After the second test week subjects were asked to choose the two shampoo they would prefer to use for the remainder of the study. 75% chose to use the PTZ conditioning shampoo over the ketoconazole shampoo (p=0.0016). Liking the shampoo significantly increased willingness to use. Among the people who preferred the PTZ shampoo (n=30), nearly three times more subjects (73%) said they would be willing to use the shampoo versus the ketoconazole shampoo (26%).
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Physicians recommending shampoos for dandruff and scalp seborrheic dermatitis, especially among female patients, should look for shampoos that not only provide excellent antifungal efficacy but also look for shampoos designed to deliver excellent hair appearance and manageability through the inclusion of conditioning ingredients in order improve patient compliance and treatment. Shampoos providing conditioning benefits from ingredients like dimethicone can provide desired hair quality benefits. Specifically this study showed: 1) The 1% PTZ conditioning shampoo clinically improved cosmetic hair quality attributes both as measured by the investigator and perceived by subjects. 2) Cosmetic benefits improved patient satisfaction with the shampoo and increased willingness to use the PTZ shampoo even if they had to purchase it themselves.