Collection of articles about dermatology from all over the world. Dermatology beyond borders.
Dermatology in Asia and Latin America: Far, but not so far
As a dermatologist dedicated to clinical dermatology seeing many patients with a variety of skin conditions, I’m always intrigued by the many diseases we have in common with our Asian colleagues.
Those conditions include pigmentary disorders (such as melasma), infections related to eating habits (such as gnathostomiasis), neoplastic diseases (such as acral lentiginous melanoma and Adult T cell Leukemia Lymphoma related to Human T-cell Lymphotropic Virus type 1) and even entities that been more recently described, such as skin manifestations of chronic Epstein Barr Virus (EBV) infections and free-living amoeba infections (Balamuthia mandrillaris).
Of course, the best explanation for such coincidences is the common genetic background of our populations. This provides even more scientific basis to diverse theories arguing that the American Continent was populated from the North to the South as a result of migratory flows from Asia, through the Behring Strait. But, might there be other explanations?
Take for example the lymphoproliferative disorders related to EBV. Initially described in Japan and Korea, similar cases of what was then called atypical Hidroa Vacciniforme affecting children and young adults were later identified in Mexico, Bolivia and Peru. This process tells us that the response to EBV infection is probably dependent of genetic factors that define how our immune system respond to the virus. On top of that, it tells us that these cases are different from, for example, what the virus causes in the African population, where the same EBV produces not Hydroa-like disease, but an endemic form of Burkitt lymphoma.
A similar observation can be made regarding a more recently described infection than concern dermatologists. I’m referring to the cutaneous and central nervous system disease caused by the free-living amoeba Balamuthia mandrillaris. The largest number of cases has so far described in two countries, the United States and Peru, but with an important difference. In Peruvian cases, the general rule is that cutaneous involvement of the central face is caused by an infiltrating plaque, only a minority of US cases develop cutaneous involvement to begin with. Interestingly, in a recently published series of cases from China (1), the authors describe the exact same clinical characteristics of cutaneous involvement seen in the Peruvian experience. One might speculate than genetic determinants of the innate immune response, common to Chinese and Peruvian populations, allow the deterrent of the infection at a skin level, rather than allowing the ameba to quickly disseminate through the blood stream to the Central Nervous System, as it seems to be the case in the US experience.
As a dermatologist that has grown from attending academic events in different countries around the world, I see the next World Congress of Dermatology in Singapore 2023, as a great opportunity to exchange ideas about issues that concern all of us. This is especially true in the fields of clinical dermatology where our experience on similar diseases may overlap. Medicine, dermatology, and most importantly, our patients, will certainly benefit from such scientific dialogue.
1. Wang L, Cheng W, Li B, Jian Z, Qi X, Sun D, Gao J, Lu X, Yang Y, Lin K, Lu C, Chen J, Li C, Wang G, Gao T. Balamuthia mandrillaris infection in China: a retrospective report of 28 cases. Emerg Microbes Infect. 2020 Dec;9(1):2348-2357.