The key to successful treatment is an accurate diagnosis.You can look up treatments, but you cannot lookup diagnoses. Without a proper diagnosis, you willbe asking ‘What's a good treatment for scaling feet?'instead of ‘What's good for tinea pedis?' Wouldyou ever ask yourself ‘What's a good treatment forchest pain? Luckily, dermatology differs from otherspecialties as its diseases can easily be seen. Keen eyesand a magnifying glass are all that are needed fora complete examination of the skin. Sometimes it isbest to examine the patient briefly before obtaining afull history: a quick look will often prompt the rightquestions. However, a careful history is important inevery case, as is the intelligent use of the laboratory.
History include descriptions of theevents surrounding the onset of the skin lesions, of theprogression of individual lesions, and of the disease ingeneral, including any responses to treatment. Manypatients try a few salves before seeing a physician. Sometry all the medications in their medicine cabinets, manyof which can aggravate the problem. A careful inquiryinto drugs taken for other conditions is often useful.Ask also about previous skin disorders, occupation,hobbies and disorders in the family.
Examination
To examine the skin properly, the lighting must beuniform and bright. Daylight is best. The patient shouldusually undress so that the whole skin can be examined,although sometimes this is neither desirable (e.g. handwarts) nor possible. The presence of a chaperone ideally a nurse or a relative, is often sensible, and isessential if examination of the genitalia is necessary.Do not be put off this too easily by the elderly, thestubborn, the shy, or the surroundings.
History of present skin condition
DurationSite at onset, details of spreadItchBurningPainWet, dry, blistersExacerbating factorsGeneral health at presentAsk about feverPast history of skin disordersPast general medical historyInquire specifically about asthma and hay feverFamily history of skin disordersIf positiveainherited vs. infection/infestationFamily history of other medical disordersSocial and occupational historyHobbiesTravels abroadRelationship of rash to work and holidaysAlcohol intakeDrugs used to treat present skin conditionTopicalSystemicPhysician prescribedPatient initiatedDrugs prescribed for other disorders (including those takenbefore onset of skin disorder)
Distribution
A dermatological diagnosis is based both on thedistribution of lesions and on their morphology andconfiguration. For example, an area of seborrhoeicdermatitis may look very like an area of atopic dermatitis;but the key to diagnosis lies in the location.Seborrhoeic dermatitis affects the scalp, forehead,eyebrows, nasolabial folds and central chest; atopicdermatitis typically affects the antecubital and poplitealfossae.See if the skin disease is localized, universal or symmetrical.Depending on the disease suggested by themorphology, you may want to check special areas,like the feet in a patient with hand eczema, or thegluteal cleft in a patient who might have psoriasis.
Morphology
After the distribution has been noted, next define themorphology of the primary lesions. Many skin diseases have a characteristic morphology, but scratching,ulceration and other events can change this. The ruleis to find an early or ‘primary' lesion and to inspectit closely. What is its shape? What is its size? What isits colour? What are its margins like? What are thesurface characteristics? What does it feel like?
There are many reasons why you should describeskin diseases properly.
• Skin disorders are often grouped by their morphology.Once the morphology is clear, a differentialdiagnosis comes easily to mind.
• If you have to describe a condition accurately, youwill have to look at it carefully
.• You can paint a verbal picture if you have to referthe patient for another opinion.
• You will sound like a physician and not a homoeopath.
Primary lesions
Secondary lesions
These evolve from primary lesions.A scale is a flake arising from the horny layer.A keratosis is a horn-like thickening of the stratumcorneum.A crust may look like a scale, but is composed ofdried blood or tissue fluid.An ulcer is an area of skin from which the whole ofthe epidermis and at least the upper part of the dermishas been lost. Ulcers may extend into subcutaneousfat, and heal with scarring.An erosion is an area of skin denuded by a completeor partial loss of only the epidermis. Erosions healwithout scarring.
An excoriation is an ulcer or erosion produced byscratching.A fissure is a slit in the skin.A sinus is a cavity or channel that permits theescape of pus or fluid.A scar is a result of healing, where normal structuresare permanently replaced by fibrous tissue.Atrophy is a thinning of skin caused by diminutionof the epidermis, dermis or subcutaneous fat. Whenthe epidermis is atrophic it may crinkle like cigarettepaper, appear thin and translucent, and lose normalsurface markings. Blood vessels may be easy to see inboth epidermal and dermal atrophy.Lichenification is an area of thickened skin withincreased markings.A stria (stretch mark) is a streak-like linear atrophicpink, purple or white lesion of the skin caused bychanges in the connective tissue.Pigmentation, either more or less than surroundingskin, can develop after lesions heal.Having identified the lesions as primary or secondary,adjectives can be used to describe them in terms oftheir other features.
• Colour (e.g. salmon-pink, lilac, violet)
• Sharpness of edge (e.g. well-defined, ill-defined)
.• Surface contour (e.g. dome-shaped, umbilicated,spire-like.
• Geometric shape (e.g. nummular, oval, irregular,like the coast of Maine)
.• Texture (e.g. rough, silky, smooth, hard).
• Smell (e.g. foul-smelling).
• Temperature (e.g. hot, warm).
Dermatologists also use a few special adjectiveswhich warrant definition
.• Nummular means round or coin-like.• Annular means ring-like.• Circinate means circular.• Arcuate means curved.
• Discoid means disc-like.
• Gyrate means wave-like.
• Retiform and reticulate mean net-like.
History include descriptions of theevents surrounding the onset of the skin lesions, of theprogression of individual lesions, and of the disease ingeneral, including any responses to treatment. Manypatients try a few salves before seeing a physician. Sometry all the medications in their medicine cabinets, manyof which can aggravate the problem. A careful inquiryinto drugs taken for other conditions is often useful.Ask also about previous skin disorders, occupation,hobbies and disorders in the family.
Examination
To examine the skin properly, the lighting must beuniform and bright. Daylight is best. The patient shouldusually undress so that the whole skin can be examined,although sometimes this is neither desirable (e.g. handwarts) nor possible. The presence of a chaperone ideally a nurse or a relative, is often sensible, and isessential if examination of the genitalia is necessary.Do not be put off this too easily by the elderly, thestubborn, the shy, or the surroundings.
History of present skin condition
DurationSite at onset, details of spreadItchBurningPainWet, dry, blistersExacerbating factorsGeneral health at presentAsk about feverPast history of skin disordersPast general medical historyInquire specifically about asthma and hay feverFamily history of skin disordersIf positiveainherited vs. infection/infestationFamily history of other medical disordersSocial and occupational historyHobbiesTravels abroadRelationship of rash to work and holidaysAlcohol intakeDrugs used to treat present skin conditionTopicalSystemicPhysician prescribedPatient initiatedDrugs prescribed for other disorders (including those takenbefore onset of skin disorder)
Distribution
A dermatological diagnosis is based both on thedistribution of lesions and on their morphology andconfiguration. For example, an area of seborrhoeicdermatitis may look very like an area of atopic dermatitis;but the key to diagnosis lies in the location.Seborrhoeic dermatitis affects the scalp, forehead,eyebrows, nasolabial folds and central chest; atopicdermatitis typically affects the antecubital and poplitealfossae.See if the skin disease is localized, universal or symmetrical.Depending on the disease suggested by themorphology, you may want to check special areas,like the feet in a patient with hand eczema, or thegluteal cleft in a patient who might have psoriasis.
Morphology
After the distribution has been noted, next define themorphology of the primary lesions. Many skin diseases have a characteristic morphology, but scratching,ulceration and other events can change this. The ruleis to find an early or ‘primary' lesion and to inspectit closely. What is its shape? What is its size? What isits colour? What are its margins like? What are thesurface characteristics? What does it feel like?
There are many reasons why you should describeskin diseases properly.
• Skin disorders are often grouped by their morphology.Once the morphology is clear, a differentialdiagnosis comes easily to mind.
• If you have to describe a condition accurately, youwill have to look at it carefully
.• You can paint a verbal picture if you have to referthe patient for another opinion.
• You will sound like a physician and not a homoeopath.
Primary lesions
- Erythema is redness caused by vascular dilatation.
- A papule is a small solid elevation of skin, less than0.5 cm in diameter.
- A plaque is an elevated area of skin greater than2 cm in diameter but without substantial depth.
- A macule is a small flat area of altered colour ortexture.
- A vesicle is a circumscribed elevation of skin, lessthan 0.5 cm in diameter, and containing fluid.
- A bulla is a circumscribed elevation of skin over0.5 cm in diameter and containing fluid.A pustule is a visible accumulation of pus in theskin.
- An abscess is a localized collection of pus in acavity, more than 1 cm in diameter. Abscesses are usually nodules, and the term ‘purulent bulla' is sometimes used to describe a pus-filled blister that is situatedon top of the skin rather than within it
- .A wheal is an elevated white compressible evanescentarea produced by dermal oedema. It is oftensurrounded by a red axon-mediated flare. Althoughusually less than 2 cm in diameter, some wheals are huge.
- Angioedema is a diffuse swelling caused by oedemaextending to the subcutaneous tissue.
- A nodule is a solid mass in the skin, usually greaterthan 0.5 cm in diameter, in both width and depth,which can be seen to be elevated or can be palpated.
- A tumour is harder to define as the term is based morecorrectly on microscopic pathology than on clinical morphology.
- A papilloma is a nipple-like projection from theskin.
- Petechiae are pinhead-sized macules of blood in theskin.
- The term purpura describes a larger macule orpapule of blood in the skin. Such blood-filled lesionsdo not blanch if a glass lens is pushed against them(diascopy).An ecchymosis is a larger extravasation of bloodinto the skin.
- A haematoma is a swelling from gross bleeding.A burrow is a linear or curvilinear papule, withsome scaling, caused by a scabies mite.
- A comedo is a plug of greasy keratin wedged ina dilated pilosebaceous orifice. Open comedones areblackheads.
- The follicle opening of a closed comedois nearly covered over by skin so that it looks like apinhead-sized, ivory-coloured papule.
- Telangiectasia is the visible dilatation of smallcutaneous blood vessels.
- Poikiloderma is a combination of atrophy, reticulatehyperpigmentation and telangiectasia.
Secondary lesions
These evolve from primary lesions.A scale is a flake arising from the horny layer.A keratosis is a horn-like thickening of the stratumcorneum.A crust may look like a scale, but is composed ofdried blood or tissue fluid.An ulcer is an area of skin from which the whole ofthe epidermis and at least the upper part of the dermishas been lost. Ulcers may extend into subcutaneousfat, and heal with scarring.An erosion is an area of skin denuded by a completeor partial loss of only the epidermis. Erosions healwithout scarring.
An excoriation is an ulcer or erosion produced byscratching.A fissure is a slit in the skin.A sinus is a cavity or channel that permits theescape of pus or fluid.A scar is a result of healing, where normal structuresare permanently replaced by fibrous tissue.Atrophy is a thinning of skin caused by diminutionof the epidermis, dermis or subcutaneous fat. Whenthe epidermis is atrophic it may crinkle like cigarettepaper, appear thin and translucent, and lose normalsurface markings. Blood vessels may be easy to see inboth epidermal and dermal atrophy.Lichenification is an area of thickened skin withincreased markings.A stria (stretch mark) is a streak-like linear atrophicpink, purple or white lesion of the skin caused bychanges in the connective tissue.Pigmentation, either more or less than surroundingskin, can develop after lesions heal.Having identified the lesions as primary or secondary,adjectives can be used to describe them in terms oftheir other features.
• Colour (e.g. salmon-pink, lilac, violet)
• Sharpness of edge (e.g. well-defined, ill-defined)
.• Surface contour (e.g. dome-shaped, umbilicated,spire-like.
• Geometric shape (e.g. nummular, oval, irregular,like the coast of Maine)
.• Texture (e.g. rough, silky, smooth, hard).
• Smell (e.g. foul-smelling).
• Temperature (e.g. hot, warm).
Dermatologists also use a few special adjectiveswhich warrant definition
.• Nummular means round or coin-like.• Annular means ring-like.• Circinate means circular.• Arcuate means curved.
• Discoid means disc-like.
• Gyrate means wave-like.
• Retiform and reticulate mean net-like.