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Abstract

To the Editor: I would like to thank Dr. Strachan and Ms Okereke for their interest in our original research article, “Hair care practices and their association with scalp and hair disorders among African American girls.”1Rucker Wright D. Gathers R. Kapke A. Johnson D. Joseph C.L.M. Hair care practices and their association with scalp and hair disorders in African-American girls.J Am Acad Dermatol. 2011; 64 (Reply 2011;64:1182): 253-262Abstract Full Text Full Text PDF PubMed Scopus (56) Google Scholar In their letter to the Editor, one of the concerns was the study survey’s use of the layman’s term “dandruff” to describe seborrheic dermatitis, which they argue could have been misunderstood by participants. Non-infantile scalp seborrheic dermatitis (SD) can clinically present with ill-defined erythematous patches associated with fine scaling or with non-inflammatory fine white diffuse scale. Dandruff is a form of mild SD.2Del Rosso J. Adult seborrheic dermatitis: a status report on practical topical management.J Clin Aesthet Dermatol. 2011; 4: 32-38PubMed Google Scholar On the survey; the actual medical term “seborrheic dermatitis” was used alongside the layman’s term “dandruff” in parentheses. Participants were asked if their “daughter ever experienced or was ever diagnosed/treated by a health care provider for this condition.” If, according to Dr Strachan and Ms Okereke, participants believed that their daughter’s “dry scalp” is not considered seborrheic dermatitis or dandruff, then that would mean our results underrepresented the actual number of girls having seborrheic dermatitis, that is, more participants selected “no” to ever having or being diagnosed/treated with SD. If participants who believed they had dry scalp actually answered “yes” to the question about dandruff, our odds ratio would have been even higher, meaning our associations would have been even stronger. We acknowledged in our article’s discussion section the limitation of self-report and possibility for misinterpretation of questions, which is inherent in any self-report survey. Nonetheless, the associations concluded in the study via statistical analysis based on a number of responses to the questions are still valid. With regard to Dr Strachan and Ms Okereke’s second issue, the design of this study does not prove causality but a significant association between reporting having seborrheic dermatitis (dandruff) and reporting the use of hair oils/grease every 2 weeks, with an odds ratio of 3.69 (95% CI, 1.07-12.7; P = .039). In other words, infrequent application of hair oil was significantly associated with seborrheic dermatitis. Based on survey data, daily application of oil is not associated with SD. As discussed in our article, the type of hair oil/grease was not specified; moreover, data on the use of sulfur-based products on African-American girls’ hair is not actually known. In regards to the frequency of shampooing, the choices on the actual survey were: once a week or more often, every 2 weeks, once a month or other, with room to write in answers. Analysis was reported from grouping responses into 2 categories: 1) every 2 to 4 weeks and 2) once per week or more frequent in order to have a sufficient sample size to perform the statistical analysis. We did analyze each category separately and the results were not statistically significant (no association with SD and frequency of shampooing). Our article does not conclude irrelevance to shampooing frequently; we acknowledge that larger sample sizes may be needed. Our paper also does not conclude that hair extensions are causal, just that there is a strong association with SD. Dr Strachan and Ms Okereke also mention in their letter interest in seeing data on hair styling frequency. The association with frequency of hair styling practices and scalp/hair disorders is planned to be published in another paper; the anticipation is welcomed. In conclusion, determining causality was not the goal of this original research design. We conducted a cross-sectional analysis which would not allow for causality given that the exposure and disease were collected at the same time. The purpose was to describe associations between certain hair care practices and scalp/hair disorders to direct future research and recommendations for hair care practices based on evidence and not anecdotes. Hair care practices and their association with scalp and hair disorders in African American girlsJournal of the American Academy of DermatologyVol. 66Issue 1PreviewTo the Editor: We read with great interest the article by Wright et al1 on the association of certain hair care practices with hair and scalp disorders in African American girls in the February 2011 issue of the Journal. The authors have made a meaningful contribution to the understanding of these conditions in an understudied demographic. We disagree, however, with some of the conclusions they come to regarding what these data suggest about seborrheic dermatitis in this population. Full-Text PDF