logo An overview of dermatology

Introduction to dermatology

An overview of dermatology

Objectives

To develop an understanding of the scope of dermatology, the training required to be a dermatologist, the epidemiology of skin diseases and their psychosocial impact

Key points

  • Dermatology is the branch of medicine that deals with skin, mucous membranes, hair and nails.
  • About 15% of consultations in general practice relate to a skin problem and between 50 and 75% of individuals may have a skin problem at any time.
  • White-skinned New Zealanders are particularly prone to conditions relating to excessive exposure to ultraviolet radiation in skin that has inadequate natural protection.
  • Skin diseases prevalent in the tropics often have infectious origins.
  • Occupational skin diseases often relate to the irritant nature of material with which workers are in contact and sometimes to immune reactions to specific allergens.
  • Hand dermatitis is the most common occupational skin problem.
  • Many skin diseases are disfiguring and abnormal appearance has a major impact on psychosocial wellbeing.
  • Disturbance of body image is particularly serious if it arises during childhood or adolescence.

Introduction

Dermatology is the branch of medicine that deals with skin, mucous membranes, hair and nails. Although relatively straightforward to examine, the skin is the largest organ and has numerous potential abnormalities - there are about 1500 distinct skin diseases and many variants. We are relatively ignorant about the pathogenesis of the majority of these although knowledge is rapidly increasing especially in the fields of molecular medicine and genetics.

This course will discuss the impact of skin diseases, outline the biology of normal skin, and describe how to examine the skin and how its diseases may be effectively treated. A range of skin infections, inflammatory skin diseases and neoplastic conditions will be briefly described as well as skin signs of systemic disease.

UK data suggests an average of 15% of consultations in general practice relate to a skin problem and between 50 and 75% of individuals may have a skin problem at any time. Although most of these are relatively harmless and asymptomatic, (warts, athletes' foot, dandruff, insect bites and so on), many result in significant disability.

Symptoms of skin disease include:

Signs may be described in terms of single areas of altered skin (lesions) or widespread eruptions. The distribution, configuration, colour, morphology, surface and secondary changes may be helpful in making a diagnosis and planning management.

Skin diseases are classified in various ways.

However, these classifications are evolving as the science of dermatology expands. The importance of genetic predisposition and immune function are increasingly recognised.

Training in dermatology

In New Zealand, intending dermatologists start with basic training in internal medicine, which usually takes 2 to 4 years as a house surgeon and medical registrar. Advanced training begins after Part 1 FRACP written and clinical examinations have been passed. It involves at least four years as a dermatology registrar in approved training centres in New Zealand (Auckland Green Lane, Middlemore and Hamilton in 2015) and overseas.

Dermatologists must have expertise in basic sciences including microbiology, pathology, immunology, biochemistry, physics, physiology, and endocrinology. A wide general medical knowledge is helpful as skin diseases are often associated with internal conditions and their treatment.

All dermatologists perform some skin surgery to remove benign and malignant skin lesions and to perform various cosmetic procedures. Subspecialty dermatological surgeons undergo extra training in microscopically controlled excision of skin cancers (Mohs surgery), facial rejuvenation, laser therapy and sclerotherapy.

The New Zealand Dermatological Society oversees a CPD certification programme for its members, as required by the Medical Council of New Zealand.

Students with an interest in this career option can find details of the training programme on DermNet..

Epidemiology of skin diseases

Certain skin problems may be more prevalent in specific populations.

_What conditions do you think white-skinned New Zealanders are particulary prone to?_ Short answer:

White-skinned New Zealanders are particularly prone to conditions relating to excessive exposure to ultraviolet radiation in skin that has inadequate natural protection. These include photoageing changes (eg. dryness, freckling, fine wrinkles) and malignancies (eg. solar keratoses, basal and squamous cell carcinoma, melanoma).

Effects of sun exposure

Black skin is particularly prone to pigmentary disorders and hypertrophic or keloidal scarring.

Pigmentary disorder

Skin diseases prevalent in the tropics often have infectious origins.

Cutaneous tuberculosis

Mycetoma


Occupational dermatological diseases often relate to the irritant nature of material with which workers are in contact and sometimes to immune reactions to specific allergens. Hand dermatitis is the most common occupational skin problem. Examples:

Hand dermatitis due to cement

Dermatitis in a hairdresser


Psychosocial impact of skin diseases

Consider the occupational and social impacts of the conditions illustrated below.

Severe acne

Vitiligo

Penile psoriasis

Haemangioma


Most dermatological conditions are highly visible and may invoke disgust, shame and self-consciousness that can have profound psychosocial effects. Disfigurement can result in negative self perception, depression, social rejection and social isolation related to unfavourable self-image. Emotional abuse, verbal abuse and bullying may take place. These in turn can lead to self-contempt, frustration and torment leading to deliberate self harm or even suicide (a recognised complication of disfiguring skin conditions such as acne).

In addition, psychiatric disorders may manifest as apparent skin disease. Therefore the management of skin diseases requires recognition of psychological aspects as well as treating the affected skin.