Student membership will be medical students attending a UK or Irish medical school.
As well as being the most visible organ in the body, the skin is also the biggest. It fulfils many diverse functions, and to do so contains lots of cell types and organelles, and appendages like hair and nail. What do you use your skin for? No prizes, but if you can write down more than 5 functions of the skin, award yourself 5 points; more than 10, 15 points; more than 15, 25 points.
The skin is in the front line of environmental attack from physical and biological agents. Each of the skin's physiological roles can malfunction. Benign and malignant tumours can develop in all of its many cell types. The skin may also be damaged as a result of disease arising elsewhere in the body. All this means that there are lots of dermatological diseases: the British Association of Dermatologists diagnostic index has over 4000 preferred terms.
Broadly speaking, skin disorders can be divided into rashes and lesions. Rashes are things like psoriasis, eczema, acne, and drug eruptions, and lesions are things like moles, warts, and benign and malignant tumours.
Nobody has a perfect skin, and a lot of lesions never reach medical attention. Skin disease generally starts to matter to people because 1) it doesn't look nice, to themselves or others 2) they don't know what might be 3) it itches or hurts 4) it might be contagious 5) it can kill them or 6) all of the above. Dermatology is about responding to all these needs.
Because skin disorders are so common and so obvious, all doctors ought to have some idea about what is and what isn't normal in the skin. Amongst purely cutaneous lesions, for some reason non-dermatologists reliably recognise only Campbell de Morgan angiomas ("associated with ageing, of no significance"). Somehow folk seem not to wonder about all the other spots on the patients whose chests they auscultate or whose tummies they prod. Would you notice the melanoma lurking amongst the moles, keratoses and other pigmented lesions? 25 points for getting it right, otherwise none. Click on an image for the answer.
Future General Practitioners: In the United Kingdom, general practitioners deal with most skin problems, which are relevant to 10-15% of consultations. GP trainees often do not discover how little they know about dermatology until they undertake their practice year. Typical presentations include various lumps and bumps, and psoriasis, eczema, and acne. Skin infections are also common. Can you identify these typical skin infections? 5 points each if you can name the causative organism. Click on an image for the answer.
Future Physicians: Physicians have kidnapped a number of cutaneous disorders for their own use, especially in final and membership examinations. Things like clubbing, spider naevi, pretibial myxoedema, necrobiosis lipoidica, acanthosis nigricans, and so on. 10 points each for identifying the medical significance of these skin lesions. Click on an image for the answer.
Future Surgeons: Surgeons, of course, need to have some idea what they are cutting out before they cut it out, in case they should cut it out differently or don't need to cut it out at all. Dermatological knowledge may often save an unnecessary biopsy.
What do dermatologists do?
British dermatologists are hospital based specialists who provide a secondary care service for the diagnosis and management of skin disease. Dermatology training in the UK involves 3 years of general professional training, and MRCP prior to specialist training.
The majority of clinical activity in dermatology takes place in out-patient units. General dermatology clinics deal with an exceptional variety of conditions. Typical and appropriate referrals in a single clinic might include presentations such as severe or refractory plaque psoriasis, various forms of eczema, nodulocystic acne, acute erythemas or blistering, chronic urticaria, hair loss, pruritus, actinic keratoses and other solar damage, basal cell carcinomas, and worrying pigmented lesions. In amongst this "bread and butter" stuff will frequently be something more unusual: granuloma annulare, morphea, lichen planus, vasculitis, lupus erythematosus, dermatomyositis, an ichthyosis…
Dermatological management is both medical and surgical. Dermatology units undertake a great deal of diagnostic and therapeutic minor surgery. Dermatological surgery is expanding and some dermatologists are exceedingly proficient in flaps, grafts and other specialised techniques. Many units also have lasers for dealing with vascular and other lesions.
Other specialist services in dermatology include contact dermatitis clinics for investigating possible occupational or other allergy, photobiology clinics, second-line clinics for management of cytotoxic and immunosuppressive therapy, and paediatric dermatology clinics. In larger units dermatologists may super-specialise in these or other areas such as cutaneous cancer & lymphoma. In addition, British dermatologists are all trained in skin pathology, and may maintain a special interest in this field.
Dermatologists work best with dedicated teams of nurses, who may also be specialists. The major workload of dermatology in- and out-patient units is in providing care for chronic inflammatory skin diseases, mainly psoriasis and eczema. The great advantage of treating the skin is the ability to target not only the organ but also the lesion, for example in plaque psoriasis. For this purpose, we use topical dressings of various time-honoured noxious and smelly potions. Of course the patients would much rather take tablets, because they can't see the adverse effects on their kidneys or liver. Fortunately, we also use phototherapy, which is clean and gives a tan, which makes people think they look healthy.
Dermatology can be fun
The sheer variety of dermatological disease provides enormous opportunities for the development of special interests and expertises. Equally, the often very basic standard of dermatological knowledge among other doctors means that one's opinion tends to be highly valued. Think of the impression created when you declare that yet another referral with "maculo-papular rash, query drug-related" is in reality a classic case of teleangiectasia macularis eruptiva perstans or, perhaps more frequently, scabies.
Mind you, many of the abstruse terms used by dermatologists are simply rather banal descriptions cobbled together from Latin and/or Greek. For example "Bullous ichthyosiform erythroderma" means "red skin with fish-like scale and blisters". 5 points each if you you can name the following skin disorders (click on an image for the answer):
Dermatologists are very social beings. In the UK there are regular clinical meetings in all regions, where one can share problems or boast of diagnostic and therapeutic triumphs. Numerous national and international meetings cater for both clinically based and academic dermatologists.
Dermatology can be serious
Malignant melanoma kills about 1500 people a year in the UK, many of them relatively young; squamous carcinoma of the skin another 500. Pigmented lesion services, together with skin cancer awareness programmes, contribute to early diagnosis and treatment, and avoidance of preventable mortality. Serious malignancies of the skin also include cutaneous lymphomas, and the skin may be the site of metastatic tumours and of cutaneous signs of malignancy.
Unlike hearts, livers or kidneys, skin rarely fails catastrophically. However severe psoriasis, eczema and other conditions can cause a state called erythroderma, when thermoregulation, fluid balance, and defence against infection are all severely impaired. Similar life-threatening consequences occur when large areas of necrotic epidermis are shed in toxic epidermal necrolysis, in adults usually due to drugs. Other conditions such as the blistering disorders, various forms of vasculitis, or granulomatous disorders can cause severe morbidity and may merit hazardous treatments.
At the other end of the scale, it is easy to underestimate the social impact of even mild skin disease. Skin disorders produce instinctive revulsion, perhaps as an evolutionary defence against infestation. When did you last see someone with psoriasis at a swimming pool, and how did you feel about it? Itch is unpleasant, and scratching unpleasant to watch. Atopic eczema keeps children awake, not to mention their parents. Hand dermatitis produces occupational handicap. Hair loss may be psychologically devastating. Psoriasis causes sexual difficulties. Even acne impairs confidence, and may affect job prospects. A dermatologist needs to understand all this, and to communicate this understanding to patients and other carers.
Science and the skin
The accessibility of the skin to observation and experimentation has long been and is still exploited. Immunologists have led the way, and diagnostic skin tests figure prominently in the history of medicine: think of Jenner, Mantoux, and others. Can you identify the types of hypersensitivity and the relevant disorders (10 points each; click on an image for the answer):
Inflammatory and immune mechanisms of general applicability are also accessible to study in skin. Skin can be artificially sensitised to study immune induction and expression. Inflammatory mediators can be injected into the skin, or blisters induced and used to follow the accumulation of cells, mediators or metabolites.
The skin has also been used to study physiology, for example the triple response of Thomas Lewis. In pharmacology, the mechanism of action of drugs can be studied by measuring their effect on cutaneous physiology or inflammatory or immune responses. New topical or oral preparations for skin disease continue to emerge, and require clinical trial to establish efficacy and safety.
In many parts of the world, leprosy and fungal and protozoal skin diseases remain major public health problems. Although tropical dermatology is of limited relevance in to UK practice, British investigators contribute importantly to the study of international problems in dermatology.
The epidemiology of skin disease in Britain is also a subject of intensive study. Important areas under investigation include the increasing prevalences of atopic eczema, and of malignant melanoma, and the relationship of environmental factors to skin disease.
In the study of neoplasia, lesions identified clinically, such as actinic keratoses, can be targetted for biopsy to look at, for example, oncogene expression. However, the mutagenic effects of UV radiation are only a part of a much larger scientific field, photobiology and photodermatology.
Skin manifestations facilitate the diagnosis of genetic disease - well known examples include neurofibromatosis and tuberose sclerosis but there are many others. In the investigation of inherited metabolic diseases or chromosomal defects, cultured skin fibroblasts may be of diagnostic value.
Skin can be biopsied to provide cells - fibroblasts, keratinocytes, melanocytes - or organs such as hair follicles for culture and use in in vitro studies. As a result of advances in molecular biology, many inherited skin disorders are now understood, but the information gained has had implications for cell biology as a whole.
Finding out more about dermatology
Dermatologists are friendly and approachable, or at worst, "mostly harmless". Their major problem tends to be coping with a large and increasing workload. Nonetheless, many would welcome the opportunity to encourage the interest of an individual medical student. If you feel exposure to dermatology in the curriculum is inadequate for you, the best way to pick up more basic knowledge is to arrange to sit in during outpatient clinics or minor surgery lists, or to try to attend clinical meetings. Academic or general dermatologists may also be able to suggest small projects, or an interesting patient to investigate and perhaps write up as a case report. It will be much harder to find time for this when you are qualified.
Qualified doctors wishing to find out more about dermatology, either as a career or for general practice, are advised to think about an SHO post, ideally for 6 months or more. However, those already intent on a career in dermatology should know they will need 3 years post registration experience and MRCP before they will be eligible for specialist training.
If you would like any further information, approach your local dermatologist.
If this web page has stimulated your interest, we look forward to hearing from you.
Professor C S Munro
Southern General Hospital