Seborrheic Dermatitis in Skin of Color: Clinical Considerations

January 2019 | Volume 18 | Issue 1 | Original Article | 24 | Copyright © January 2019


May Elgash BS,a Ncoza Dlova MBChB FCDerm PhD,b Temitayo Ogunleye MD,c Susan C. Taylor MDc

aLewis Katz School of Medicine at Temple University, Philadelphia, PA bNelson R Mandela School of Medicine, University of Kwazulu-Natal, Durban, South Africa cPerelman School of Medicine, University of Pennsylvania, Philadelphia, PA

Prognosis

SD is a benign, though chronic, relapsing condition.18 It usually responds well to conventional treatments, although it can recur. In adolescents with SD, the course is similar to adults, and relapse is common. Infantile SD is typically asymptomatic and resolves spontaneously in weeks to months.23 Given the chronic and relapsing nature of SD, it may affect the quality of life of those affected. In a study of South Africans with SD, it was found that SD in visible body areas and with groin involvement had a greater impact on a patient's quality of life (QOL).12 The goal of treatment of SD is to control and manage rather than cure.

Treatment and Clinical Considerations

There is limited literature on the treatment of SD in patients of color. While some components of treatment are similar to those used in other populations, special considerations should be considered given differences in hair type, hair washing frequency, and tendency for hypopigmentation.Traditionally, treatment includes the use of topical corticosteroids or antifungals such as ketoconazole, selenium sulfide, and zinc pyrithione-containing shampoos/creams/lotions. Immunomodulators, tar, and photo- therapy may also be used. The goal of treatment is to inhibit yeast colonization, loosen crusts and scales, and reduce inflam- mation and pruritus.3 Care must be given to the treatment choice and vehicle type as some patients, particularly African-Americans, inherently have dry and brittle hair. In the treatment of SD of the scalp, this subset may find certain shampoos and solution-based topicals too drying or irritating. Often, patients may use over- the-counter dandruff shampoos which are exceptionally drying to the hair shaft, particularly in patients of color who may use heat or chemical relaxers,24 thus resulting in fragility and hair breakage. In a study by Chappell et al25 that compared SD treatment modalities, it was found that Caucasian patients preferred antifungal foams, gels, and sprays, while black patients pre- ferred ointment or oil preparations. Emphasis on alternative, less drying treatment modalities may increase compliance and treatment success in skin of color patients, and prevent hair damage and breakage. In general, ketoconazole shampoo is utilized with caution in African-American women and care should be taken to instruct patients to apply directly to the scalp, rather than to the hair shaft.6 In men and children of color, ketoconazole shampoo may be used with less concern for hair fragility given men and children are less likely to have chemically or heat-styled hair.6 It is also important to consider the difference in hair washing frequency in certain populations, as SD of the scalp may be difficult to treat in individuals who wash their hair less frequently. In the same study, 79.4% of African American women were found to report hair washing frequency as less than once a week.25 The researchers evaluated ketoconazole 2% foam, which is applied to the scalp and left in, versus ketoconazole 2% shampoo, which requires washing, for treatment of SD in African-American females. The prospective, investigator initiated, parallel-group, open label, cross-over trial found that both shampoo and foam are effective at reducing SD disease severity, but foam users were more likely to be very satisfied with their results despite lower compliance. It is thought that these findings may be a result of better penetration of the foam due to its alcohol base and longer contact time. Thus, methods that require less frequent hair washing are likely to be more efficacious in this group. Finally, hypopigmentation is a common occurrence in skin of color patients with SD. This tends to resolve with treatment. A study by High and Pandya26 studied 1% Pimecrolimus in the treatment of SD for African American patients with associated hypopigmentation. In the study, five African American adults with SD applied a thin layer of pimecrolimus to the affected areas twice daily for 16 weeks. Measures of improvement examining erythema, pruritus, scaling, and hypopigmentation and were objectively measured using a mexameter. Improvement was seen not only in erythema and scaling, but also in associated hypopigmentation. Medications in this class, including tacrolimus, may be a good option for resistant cases of SD as well as to avoid the side effects of long-term topical steroid use such as skin atrophy, tachyphylaxis, and perioral dermatitis.

Prevention

Given the relapsing and remitting nature of SD, reducing the frequency of flare is key. Once SD is under control, it is important to emphasize that infrequent hair washing may lead to product build-up in the scalp which may further contribute to irritant dermatitis and seborrheic dermatitis.27 Shampooing once weekly or once every two weeks is advised for women of African descent with tightly coiled hair.6 A common practice in skin of color patients, particularly African-Americans, of applying pomades and oils to the scalp should also be avoided. Patients may use these products to mask dry flakes, or because they believe flaking represents a dry scalp, but these products often worsen SD by causing scalp irritation.24 Instead, dermatologists can advise the use of hair emollients on the hair shaft as opposed to the scalp.28 Furthermore, hair styling practices and their effect on SD have been studied. A cross-sectional survey conducted by Rucker Wright et al29 looked at various hair styling practices among African-American girls aged 1-15 years and the prevalence of scalp/hair disorders among this cohort. The study reported a significant association between SD and the use of added hair extensions and infrequent hair oil application (every two weeks). The authors propose hair extension use may lead to scalp irritation, which may cause scalp inflammation and SD.