What is "ethnic skin"?

One of my bibles of clinical medicine is Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology. It's basically a field guide to skin, with hundreds of pictures matched up with brief summaries. The introduction states, "We have endeavored to include information relevant to gender dermatology and a large number of images showing skin disease in different ethnic populations." The book devotes a section on each disease to racial differences. For example, the section on superficial spreading melanoma (p. 312) states that "white-skinned persons overwelmingly predominate. Only 2% [of cases] in brown-or black-skinned. Furthermore, brown and black persons have melanomas usually occurring on the extremities; half of brown and black persons [presumably those with melanoma] have primary melanomas arising on the sole of the foot." However, the pictures in this section show only fair-skinned patients, limiting its utility if you have any dark-skinned patients.

While fair-skinned people may make up the majority of melanoma
patients, if you work in a community where dark skin predominates, then
most of your melanoma patients will have dark skin.

The ethnic skin book, while not being comprehensive, has a useful
section on melanoma. It shows a couple of pictures of melanomas in
dark-skinned people and explains that while rarer than in whites, the
cancers can often hide in areas that are not sun-exposed, which changes
the way in which you evaluate these patients vs. light-skinned
patients. It also parses out an interesting statistic that, while most
blacks who get melanoma get it on the extremities instead of
sun-exposed areas, melanomas on the bottom of the feet actually have a
similar rate in blacks and whites. They are easy to miss, and with
melanoma, early detection saves lives.

I take care of a population that is white, black, Asian, south
Asian, but rarely Hispanic. I see a wide variety of skin types and skin
lesions. I cannot count the number of times I've heard a young doctor
tell me, "I'm not sure if the area is reddened because they have very
dark skin." (This not often comes from a doctor who isn't all that
fair-skinned either). Dark skin looks different when inflamed than
light skin, and experience helps identify the difference. I looked
through Fitzpatrick to see if this was made explicit. For common fungal
infections of the skin, Fitzpatrick shows the firey red appearance on
white skin but not the dark appearance on darker skin.

The Johnson book also has specific sections devoted to normal skin
changes in black patients, and skin disorders that are more specific to
black patients. I couldn't find ash in Fitzpatrick, which might help
explain the frequency of young, white doctors getting lectured by
elderly black woman on ashy skin.

Both books are useful,
well-worn, and rarely make it back onto my bookshelf.  But I really
wish I didn't have to buy two separate books. 

References

Wolff K, et al. Fitzpatrick's Color Atlas and Synopsis of Clinical Dermatology, 5th ed. McGraw-Hill 2005.

Johnson B, et al. Ethnic Skin, Medical and Surgical, Mosby 1998.