Dermatology
Dermatology (from Greek , "skin") is a branch of medicine dealing with the skin and its appendages (hair, sweat glands, etc).

# Scope of the field
Dermatologists are physicians (Medical Doctors) specializing in the diagnosis and treatment of diseases and tumors of the skin and its appendages. There are medical and surgical sides to the specialty. Dermatologic surgeons practice skin cancer surgery (including Mohs' micrographic surgery), laser surgery, photodynamic therapy (PDT) and cosmetic procedures using botulinum toxin ('Botox'), soft tissue fillers, sclerotherapy and liposuction. Dermatopathologists interpret tissue under the microscope (histopathology). Pediatric dermatologists specialize in the diagnoses and treatment of skin disease in children. Immunodermatologists specialize in the diagnosis and management of skin diseases driven by an altered immune system including blistering (bullous) diseases like pemphigus. In addition, there is a wide range of congenital syndromes managed by dermatologists.

# Subspecialties
The skin is the largest organ of the body and the most visible. Although many skin diseases are isolated, some are manifestations of internal disease. Hence, a dermatologist is schooled in aspects of surgery, rheumatology (many rheumatic diseases can feature skin symptoms and signs), immunology, neurology (the "neurocuteaneous syndromes", such as neurofibromatosis and tuberous sclerosis), infectious diseases and endocrinology. The study of genetics is also becoming increasingly important.

## Venereology and phlebology
Venereology, the subspecialty that diagnoses and treats sexually transmitted diseases, and phlebology, the specialty that deals with problems of the superficial venous system, are both part of a dermatologist's expertise.

## Cosmetic dermatology
Cosmetic dermatology has long been an important part of the field, and dermatologists have been the primary innovators in this area. In the 1900's dermatologists employed dermabrasion to improve acne scarring and fat microtransfer was used to fill in cutaneous defects. More recently, dermatologists have been the driving force behind the development and safe and effective employment of lasers, new dermal filling agents (collagen and hyaluronic acid), botulinum toxin ("Botox"), nonabrative laser rejuvenation procedures, intense pulsed light systems, photodynamic therapy, and chemical peeling.

## Dermatologic surgery
Dermatologic surgery (dermasurgery) is performed by all dermatologists.  Surgery is an integral part of dermatology residency training; thus all dermatologists are well trained in cutaneous surgery. In North America specialized training through a 1 year dermatologic surgery fellowship is available upon completion of the dermatology residency, and usually focuses on training in Mohs' micrographic surgery. Most dermatologic surgeons who have a special interest in this field apply for fellowship status in the American Society for Dermatologic Surgery, a professional organization dedicated to supporting and educating these physicians.
Techniques available to a dermatologic surgeon include lasers, traditional scalpel surgery, electrosurgery, cryosurgery, photodynamic therapy, liposuction, blepharoplasty (cosmetic eyelid surgery), minimally-invasive facelift surgery (e.g., the S-lift), and a variety of topical and injectable agents such as dermal fillers including fat transfer and hyaluronic acid.  Some specially trained dermatologic surgeons perform Mohs' surgery, which can be an effective method for the treatment of recurrent, indistinct, or difficult skin cancers.

# Diagnosis
Any mole that is irregular in color or shape should be examined by a dermatologist to determine if it is a malignant melanoma, the most serious and life-threatening form of skin cancer. Following a visual examination and a dermatoscopic exam (an invaluable new instrument that illuminates a mole without reflected light), a dermatologist may biopsy a suspicious mole. If it is malignant, it will be excised in the dermatologist's office.

## Medical history
The first step of any contact with a physician is the medical history. In order to classify a cutaneous eruption, the dermatologist will ask detailed questions on the duration and temporal pattern of skin problems, itching or pain, relation to food intake, sunlight, over-the-counter creams and clothing. When an underlying disease is suspected, an additional detailed history of related symptoms will be elicited (such as arthritis in a suspected case of lupus erythematosus).

## Physical examination
Dermatology has the obvious benefit of having easy access to tissue for diagnosis. Physical examination is generally done under bright light and preferably involves the whole body.  At this stage, the doctor may apply Wood's light, which may aid in diagnosing types of mycosis or demonstrate the extent of pigmented lesions, or use a dermatoscope which enlarges a suspected lesion and visualizes it without reflected light.  The dermatoscope is helpful in differentiating a benign naevus from melanoma or a seborrheic keratosis from a mole. A morphological classification of dermatological lesions is important in the diagnosis of dermatological disorders. Dermatologic diagnosis is often dependent upon pattern recognition of lesions and symptoms.

## Microbiology
Culture or Gram staining of suspected infectious lesions may identify a pathogen and help direct therapy.

## Biopsy
If the diagnosis is uncertain or a cutaneous malignancy is suspected, the dermatologic surgeon may perform a small punch biopsy (using a local anesthetic) for examination under the microscope by the dermatologist who is a trained dermatopathologist.

# Therapy
The skin is obviously accessible to topical local therapy. Antibiotic creams can help eliminate infections, while inflammatory skin diseases (such as eczema and psoriasis) often respond to steroid creams or topical anthralin. Dermatologists are innovators of new immune enhancing treatments, like topical imiquimod for superficial cancers and injection immunotherapy for warts as discussed below.

## Topical medications
Topical medications treat many dermatological diseases, but dermatologists also use oral medications. Antibiotics and immune suppressants or immune enhancing agents (injection immunotherapy or topical imiquimod) for dermatological diseases or tumors. Isotretinoin ("Accutane") is used for severe cystic acne vulgaris and often produces a lifetime remission of this disfiguring disease. Isotretinoin prescribing in the U.S. is now controlled by a cumbersome FDA governmental website called iPLEDGE. Various new modalities of treatment are in the foray; with the advent of laser technology things are quite promising.

## Photomedicine
Photomedicine involves the use of ultraviolet light, often in combination with oral or topical agents, to treat skin disease (e.g., psoriasis or mycosis fungoides).

## Surgical therapies
Surgical intervention by a dermatologic surgeon may be necessary, for example, to treat varicose veins or skin cancer. Varicose veins can be treated with sclerotherapy (injecting an agent that obliterates the vein) or the long-pulsed Nd:YAG laser. Skin cancers can be managed with excision (including Mohs cancer surgery), cryosurgery, x-ray, or with the recent topical immune enhancing agent imiquimod.  (See above section on "Dermatologic Surgery" for more details.)

## Psychodermatology and hypnodermatology
Psychodermatology and hypnodermatology involve using hypnosis in combination with other pseudo-psychological therapies to treat skin disorders.

# Training programs

## Residency training program in North America
A minimum of 12 years of college and post graduate training is required to become a dermatologist in the United States and Canada.  This includes graduation from a 4-year college where they will take Pre-Medicine, then a 4-year medical school followed by a year of post graduate training in medicine, surgery or pediatrics (called an internship) after which a physician may apply for admission to  graduate dermatology residency training.  Dermatology residencies are the most competitive in terms of admission. Following the successful completion of formal residency training in dermatology (3 years) the physician is qualified to take certifying board examinations (written) by the American Board of Dermatology or the American Osteopathic College of Dermatology.  Once board certified, dermatologists become Diplomates of the American Board of Dermatology or the American Osteopathic College of Dermatology AOCD. They are then eligible to apply for fellowship status in the American Academy of Dermatology.  Some dermatologists undertake advanced subspecialty training in programs known as fellowships after completion of their residency training. These fellowships are either one or two years in duration. Fellowships in dermatology include pediatric dermatology, surgical dermatology including Mohs micrographic surgery, dermatopathology (pathology of skin diseases) and dermatological immunology.

## Training programme in Australia
An Australian specialist dermatologist will have completed 4-6 years of medical school (depending on institution), one internship year and at least one year of general medical or surgical service in the public hospital system, prior to becoming eligible for specialist training in dermatology. The selection process is rigorous and transparent; candidates must pass science and pharmacology exams and engage in monitored and assessed practical training in all aspects of medical and surgical dermatology. At the completion of the 5 year training programme, trainees sit a national written examination held over two days. Successful candidates may then proceed to the practical viva examination, similarly held over 2 days. Successful candidates may then apply for Fellowship status with the Australasian College of Dermatologists.

## Training program in India
To be a dermatologist in India, a minimum of 2 years (for diploma ) or 3 years (for MD) of training is required after graduation from medical school and internship. The period involves rigorous training in all aspects of general dermatology, cosmetic dermatology, dermatopathology, dermatosurgery, venereal diseases (including HIV) and leprosy. At the end of the training period the resident has to go through written tests and clinical exams.  The postgraduate qualification awarded is DVD (Diploma in Venereology and Dermatology) and MD (dermatology, venereology and leprosy). Many specialists also go for certification by the national board (for the award of 'diplomate of national board').  The Indian Association of Dermatologists, Venereologists and Leprologists(IADVL)is one of the largest dermatolological associations in the world.

# Research
From the basic science of cutaneous genetics and immunology, to the practical application of new knowledge and technology in the diagnosis and management of skin disease (like psoriasis) and surgical treatment of skin cancer, dermatologists have been among the leaders in the field. The annual meeting of the American Academy of Dermatology is one of the keys for rapid dissemination of new knowledge to the practicing dermatologist and dermatologic surgeon.

# Dermatological diseases
- List of dermatological diseases

# History
The work De morbis cutaneis ("On the diseases of the skin" - 1572) by Geronimo Mercuriali from Forli (Italy) is known as the first scientific tractation about Dermatology.  Early photographic documentation of skin diseases was produced by Balmanno Squire, Dr. Alfred Hardy, Dr. A. de Montmeja, Dr. Howard Franklin Damon, Dr. George Henry Fox and Dr. Oscar G. Mason in the latter 1800s.

# Notes
-  Wu JJ, Tyring SK. ""...has been the most competitive of all specialties for at least the last 5-6 years." This is confirmed by data from the electronic residency application service (ERAS)". Retrieved 2007-06-23.CS1 maint: Uses authors parameter (link) .mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"\"""\"""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{display:none;font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
-  Wu JJ, Ramirez CC, Alonso CA et al. ""Dermatology continues to be the most competitive residency to enter..." Arch Dermatol. 2006;142:845-850". Retrieved 2007-06-25.CS1 maint: Uses authors parameter (link) CS1 maint: Explicit use of et al. (link)

# Further reading
- Dermatology Times - a newsmagazine