Dermatopatholgy is the study of skin disease at a microscopic level. It encompasses both the diagnosis of individual patients through the examination of skin biopsies, and the study of the causes, or pathogenesis of skin diseases at the cellular level.
Dermatologists recognize most skin diseases based on their appearance, distribution on the body and behaviour with time. Occasionally, these criteria are not enough and a skin biopsy is taken to be examined under the microscope. This microscopic examination reveals the histology of the disease and clarifies the diagnosis. Occasionally, additional testing needs to be performed on skin samples, such as immunofluorescence, electron microscopy or flow cytometry.
One of the greatest challenges of dermatopathology is the high number of different skin diseases. There are an estimated 1500 different rashes and skin tumors, including variants, and not one doctor who has seen them all. Therefore, dermatology and dermatopathology are among the most complex specialties of Medicine.
Certification in dermatopathology in the United States requires the completion of four years of medical school, followed by residency training of three years in either dermatology or anatomic pathology. Following that, an additional one to two years of dermatopathology training are completed. For trainees with a background in Pathology, the training includes the equivalent of 6 months of clinical dermatology, and for those whose training is in Dermatology, six months of training in Pathology are requisite. Dermatopathology is considered the most competitive fellowship in Pathology. In the United States, he(she) is first certified by the American Board of Pathology or dermatology, or the American Osteopathic Board of Pathology or Dermatology, then obtains subspecialty board certification in dermatopathology. Since 2003, the International Board of Dermatopathology certifies candidates from countries other than the United States by a test given in Europe.