Chicago — Diagnosing and treating dermatologic conditions in skin of color is a growing area of dermatology and one that requires a different approach than for lighter color skin.
Chicago - Diagnosing and treating dermatologic conditions in skin of color is a growing area of dermatology and one that requires a different approach than for lighter color skin.
He recommends, "palpating almost all patches to find any papules that are not visibly noticed but can be picked up by touch." Dr. DeLeo offered this and other helpful information, including a literature review, regarding eczema and contact dermatitis in darker skin types during a presentation here at the American Academy of Dermatology's Academy '05. He is chair of dermatology at St. Luke's-Roosevelt and Beth Israel Medical Centers, New York.
"By 2050, half of the U.S. population will be Fitpatrick III, IV or V as a result of immigration and routine population changes," he reports.
"In dermatology, certain conditions affect people with darker skin more, and certain conditions are more bothersome in darker skins." Dr. DeLeo cites pseudofolliculitis barbae in African American men, as well as vitiligo and melasma in anyone with skin of color.
While that concept is documented and well understood, it is unclear if skin of color is more likely to suffer irritation in general. He says prior research has not shown a conclusive answer.
"Depending on how the studies are done, there is no generally accepted wisdom in this area," Dr. DeLeo explains. "In the beginning, it was thought that African American skin was more resistant to irritation than white skin, and that may be true, but there are studies on both sides of the issue."
However, he says one thing is certain: "Irritation in darker skin can lead to dyspigmentation," with more social and cosmetic ramifications than in lighter skin.
"Further study needs to be done as to the irritant potential in blacks as compared to whites. If blacks do get irritated, they are more likely to develop dyspigmentation," he tells Dermatology Times.
Different allergen sensitivities
He did highlight one study that demonstrated that differing skin colors appear to have different sensitivities to certain allergens. (DeLeo, V., et al, "The Effect of Race and Ethnicity on Patch Test Results;" JAAD (2002) 46:5107-5112). The study found different response rates between Caucasian and black patients who were tested with 41 different allergens common to the standard patch test.
Of particular interest is the statistically significant and high response rate of blacks to the hair dye allergen para-phenylenediamene. Also of note is a trend in high reactivity of Caucasians to formaldehyde and formaldehyde-releasing preservatives as compared with blacks. Both results have implications to the diagnosis and treatment of eczema and contact dermatitis.
Dr. DeLeo says that diagnosing facial dermatitis in a black patient "should increase the level of suspicion," about hair dye allergens. "You might want to patch test them more quickly because we do have some information that they react more," to para-phenylenediamene.
He says one suspected reason for the frequent hair dye allergy among blacks could be that darker shades of hair dyes have a higher concentration of para-phenylenediamene than lighter shades.
The formaldehyde reaction trend among Caucasians may have implications to darker-skinned patients. Dr. DeLeo says blacks are more likely to use ointments, which contain fewer preservatives and, therefore, they do not have the exposure to formaldehyde and formaldehyde-releasing preservatives commonly found in body lotions.