Dermatology

(from Greek derma, "skin")

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Dermatology is the specialty of medicine concerned with the skin and with the skin appendages (hair, nails, sweat glands, etc.). A physician specializing in dermatology is called a dermatologist. Dematologists act both to improve the condition of normal skin and to combat disease. Some of the abnormalities of skin and hair stem from diseases in the skin itself, and others are manifestations of disease affecting the entire body (systemic disease).

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 and allergy. In addition, there are a wide range of congenital syndromes managed by dermatologists.

Training Program

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, 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 among the most competitive. Following the successful completion of formal residency training in dermatology (3 years) the physician is qualified to take certifying board examinations (written and oral) 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 program in Australia

An Australian specialist dermatologist will have completed 6 years of medical school, 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 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 (held over 2 days) after which they may apply for fellowship status with the Australian College of Dermatologists.

Training program in India

To be a dermatologist in India, a minimum of 3 years of training is required after graduation from medical school and internship. The period involves rigorous training in all aspects of general dermatology, cosmetic dermatology, 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 degree awarded is MD (dermatology, venereology and leprosy). Most specialists also go for certification by the national board (for the award of 'diplomate of national board').

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.This is likely because the diagnosis of syphilis, the most important venereal disease in past centuries, previously relied on recognition of the rashes and skin manifestations of that infection.

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"), nonablative laser rejuvenation procedures, intense pulsed light systems, photodynamic therapy, and chemical peeling.

Dermatologic Surgery

Dermatologic surgery (sometimes referred to as "Dermasurgery") is surgery performed by a dermatologipt physician. A dermatologic surgeon (sometimes known as a "Dermasurgeon") is a dermatologist with a special interest in this field who has applied 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 cancer 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

Since the skin is accessible to topical therapy, many dermatologic medications are in the form of creams, ointments, and lotions. 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 life-time 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 (eg. 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.)

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 manifestations of diseases

• List of dermatological diseases
• Cafe au lait skin patches

See also

• dermatopathology
• skin
• hair

External links

• British Association of Dermatologists
• American Academy of Dermatology
• DMOZ - Skin Conditions, Diseases, Disorders
• DermatologyChannel - Your Dermatology Community
• Dermatology Review - A dermatology forum
• SWISDOM / DOIT-Dermatology Online with Interactive Technology
• On-line Dermatology Journal Club (via JournalReview.org)
• Journal Watch Dermatology
• Skin diseases and disorders - dermatology atlas
• American Society for Dermatologic Surgery
• American Society for Mohs Surgery
• National Psoriasis Foundation
• American Society for Laser Medicine and Surgery
• Australasian College of Dermatologists
• Telederm.org - Freely Available Online Consultations in Dermatology