Detection of bursae, tendon pathology and osteophytes
Magnetic resonance imaging Joint and bone structure; soft-tissue imaging
Computed tomography High-resolution scans of thorax for pulmonary fibrosis
vertebral assessment for fractures
Synovial fluid microscopy Inflammatory cells, e.g. ↑ neutrophils in bacterial infection
Negatively birefringent needle-shaped crystals – monosodium urate monohydrate (gout)
Bacteriological culture Organism may be isolated from synovial aspirates
Biopsy and histology Synovitis – RA and other inflammatory arthritides
RA, rheumatoid arthritis; SLE, systemic lupus erythematosus.
OSCE example 1: Right shoulder pain
Mr Hunt, 38 years old, has a 2-month history of right shoulder pain with no history of trauma.
• Introduce yourself and clean your hands.
• Expose both of the patient’s shoulders and arms.
• Comment on acromioclavicular deformity and muscle wasting; look for winging of the scapula.
• Compare the right shoulder to the normal left shoulder.
• Finally, examine the arm, looking for conditions such as biceps rupture.
• If all movements of the shoulder are normal, conduct a full examination of the neck.
• Thank the patient and clean your hands.
Suggest a differential diagnosis
post-traumatic), long head of biceps rupture and referred pain from the neck.
282 • The musculoskeletal system
• Introduce yourself and clean your hands.
• In this case there is swelling of two MCP joints on the right, and one PIP joint on the left.
• Normal nails and skin (therefore psoriatic arthropathy is unlikely).
• Ask first what is sore and seek permission to examine gently.
• Tender, soft swelling of the MCP and PIP joints in the hands and left elbow.
• In feet: tender across her MTP joints on squeeze test but no palpable swelling.
in limitation of hand function.
Suggest a differential diagnosis
Suggest initial investigations
Integrated examination sequence for the locomotor system
• Ask the patient to undress to their underwear.
• Ask the GALS (gait, arms, legs, spine) questions and perform the GALS screen.
• Identify which joints require more detailed examination:
• What is the pattern of joint involvement?
• Is it likely to be inflammatory or degenerative?
• Assess the general appearance:
• Look for pallor, rashes, skin tightness, evidence of weight or muscle loss, obvious deformities.
• Check the surroundings for a temperature chart, walking aids and splints, if appropriate.
• Examine the relevant joint, or all joints if systemic disease suspected:
• Ask about tenderness before examining the patient.
• Look at the skin, nails, subcutaneous tissues, muscles and bony outlines.
• Feel for warmth, swelling, tenderness, and reducibility of deformities.
• If systemic disease is suspected, go on to examine all other systems fully.
• Consider what investigations are required:
• Joint aspiration for synovial fluid analysis or culture.
Common presenting symptoms 285
Past medical and drug history 285
Supplementary examination techniques 291
OSCE example 2: Pigmented lesion 293
Integrated examination sequence for the skin 293
284 • The skin, hair and nails
Dermatological conditions are very common (10–15% of general
practice consultations) and present to doctors in all specialties.
In the UK, 50% are lesions (‘lumps and bumps’), including skin
cancers, and most of the remainder are acute and chronic
inflammatory disorders (‘rashes’), including infections, with genetic
conditions accounting for a small minority.
Dermatological diagnosis can be challenging: not only is there a
vast number of distinct skin diseases, but also each may present
with a great variety of morphologies and patterns determined by
intrinsic genetic factors, with the diagnostic waters muddied still
further by external influences such as rubbing and scratching,
infection, and well-meaning attempts at topical and systemic
treatment. Even in one individual, lesions with the same pathology
can have a very variable appearance (for example, melanocytic
naevi, seborrhoeic keratoses and basal cell carcinomas).
Many skin findings will have no medical significance, but it is
important to be able to examine the skin properly in order to
identify tumours and rashes, and also to recognise cutaneous
signs of underlying systemic conditions. The adage that the skin
is a window into the inner workings of the body is entirely true,
and an examination of the integument will often provide the
discerning clinician with important clues about internal disease
processes, as well as with information about the physical and
psychological wellbeing of an individual.
The skin is the largest of the human organs, with a complex
anatomy (Fig. 14.1) and a number of essential functions
(Box 14.1). It has three layers, the most superficial of which
is the epidermis, a stratified squamous epithelium, containing
melanocytes (pigment-producing cells) within its basal layer, and
Langerhans cells (antigen-presenting immune cells) throughout.
The dermis is the middle and most anatomically complex layer,
containing vascular channels, sensory nerve endings, numerous
cell types (including fibroblasts, macrophages, adipocytes and
smooth muscle), hair follicles and glandular structures (eccrine,
sebaceous and apocrine), all enmeshed in collagen and elastic
tissue within a matrix comprising glycosaminoglycan, proteoglycan
The deep subcutis contains adipose and connective tissue.
Dermatoses (diseases of the skin) may affect all three
layers and, to a greater or lesser extent, the various functions
Fig. 14.1 Structures of the skin.
Deep cutaneous vascular plexus
• Protection against physical injury and injurious substances, including
• Anatomical barrier against pathogens
• Appreciation of sensation (touch, temperature, pain)
• Absorption – particularly fetal and neonatal skin
• Psychosexual and social interaction
Hair plays a role in the protective, thermoregulatory and sensory
functions of skin, and also in psychosexual and social interactions.
There are two main types of hair in adults:
• vellus hair, which is short and fine, and covers most of the
• terminal hair, which is longer and thicker, and is found on
trunk and limbs, as well as scalp, eyebrows, eyelashes,
and pubic, axillary and beard areas.
Abnormalities in hair distribution can occur when there is
transitioning between vellus and terminal hair types (for example,
hirsutism in women) or vice versa (androgenic alopecia). Hairs
undergo regular asynchronous cycles of growth and thus, in
health, mass shedding of hair is unusual. Hair loss can occur as a
result of disorders of hair cycling, conditions resulting in damage
to hair follicles (such as purposeful removal in trichotillomania),
or structural (fragile) hair disorders.
The nail is a plate of densely packed, hardened, keratinised cells
produced by the nail matrix. It serves to protect the fingertip
and aid grasp and fingertip sensitivity. The white lunula at the
base of the nail is the visible distal aspect of the nail matrix (Fig.
14.2). Fingernail regrowth takes approximately 6 months, and
toenail regrowth 12–18 months.
The possible diagnoses in dermatological conditions are broad
and some diseases have pathognomonic features. Thus, in order
to ensure that your history taking is focused and relevant, it
may be appropriate to ask to glimpse the lesion or rash before
embarking on detailed enquiry.
• a rash: scaly, blistering or itchy
• hair loss or excess hair (hirsutism, hypertrichosis)
• When did the lesion appear or the rash begin?
• Has the rash spread, or the lesion changed, since its
• Is the lesion tender or painful? Is the rash itchy? Is the itch
intense enough to cause bleeding by scratching or to
disturb sleep, as in atopic eczema and lichen simplex? Are
• Do the symptoms vary with time? For example, the
pruritus of scabies is usually worse at night, and acne
and atopic eczema may show a premenstrual
• Were there any preceding symptoms, such as a
sore throat in psoriasis, a severe illness in telogen
effluvium, or a new oral medication in drug
• Are there any aggravating or relieving factors? For
example, exercise or exposure to heat may precipitate
• What, if any, has been the effect of topical or oral
medications? Self-medication with oral antihistamines may
ameliorate urticaria, and topical glucocorticoids may help
• Are there any associated constitutional symptoms,
such as joint pain (psoriasis), muscle pain and
weakness (dermatomyositis), fever, fatigue or
• Very importantly, what is the impact of the rash on the
Ask about general health and previous medical or skin conditions;
a history of asthma, hay fever or childhood eczema suggests
atopy. Coeliac disease is associated with dermatitis herpetiformis.
Take a full drug history, including any recent oral or topical
prescribed or over-the-counter medication. Enquire about allergies
not just to medicines but also to animals or foods.
Fig. 14.2 Structure of the nail. A Dorsal view. B Cross-section.
Proximal nail fold (paronychium)
286 • The skin, hair and nails
Enquire about occupation and hobbies, as exposure to chemicals
may cause contact dermatitis. If a rash consistently improves
when a patient is away from work, the possibility of industrial
dermatitis should be considered. Ask about alcohol consumption
Document foreign travel and sun exposure if actinic damage,
tropical infections or photosensitive eruptions are being considered.
The risk of squamous cell and basal cell cancers increases
with total lifetime sun exposure, and intense sun exposures
leading to blistering burns are a risk factor for melanoma. The
susceptibility of an individual to sun-induced damage can be
determined by defining their skin type using the Fitzpatrick scale
Ask about a family history of atopy and skin conditions.
The history of a skin disorder alone rarely enables a definite
diagnosis, with perhaps the occasional exception: an itchy eruption
that resembles a nettle rash, the individual components of which
last less than 24 hours, is very likely to be urticaria; and an
intensely itchy eruption that affects all body areas except the
head (in adults) and is worse in bed at night should be considered
to be scabies until proved otherwise.
Proper assessment of the skin involves all the human senses,
with the exception of taste. Once we have listened to the
patient’s history, we look at the rash or lesion, touch the skin,
and occasionally use our sense of smell to diagnose infection
and metabolic disorders such as trimethylaminuria (fish odour
Examination of the skin should be performed under conditions
of privacy in an adequately lit, warm room with, when appropriate,
a chaperone present (p. 20). The patient should ideally be
undressed to their underwear. Routinely, the hair, nails and oral
cavity (p. 187) should be examined, and the regional lymph
nodes (p. 33) palpated. Assess skin type using the Fitzpatrick
In documenting the appearance of a lesion or rash, use the
correct descriptive terminology (Box 14.3); doing so often helps
crystallise the diagnostic thought processes.
The distribution of a dermatosis can be very informative. Is the
eruption symmetrical? If so, it is likely to have a constitutional
basis, and if not, it may well have an extrinsic cause. This
golden rule has occasional exceptions (such as lichen simplex)
but holds true in the majority of instances. Its application will
almost always prevent the common misdiagnosis of ‘bilateral
cellulitis’ (bacterial infection) of the legs, which in actuality is
usually lipodermatosclerosis or varicose eczema; bacteria are
not known for their sense of symmetry!
The pattern of a rash may immediately suggest a diagnosis: for
example, the antecubital and popliteal fossae in atopic eczema
(Fig. 14.3A); the extensor limb surfaces, scalp, nails and umbilicus
in psoriasis (Fig. 14.3B); the flexural aspects of the wrists and
the oral mucous membranes in lichen planus; the scalp, alar
grooves and nasolabial folds in seborrhoeic dermatitis; and the
sparing of covered areas in photosensitive eruptions. Does the
rash follow a dermatome (as with shingles), or Langer’s lines of
skin tension (as with pityriasis rosea), or Blaschko (developmental)
lines (as with certain genetic disorders)? The localisation of an
eruption to fresh scars or tattoos may be a manifestation of
sarcoidosis, and the anatomical location may provide a clue to
diagnosis, such as the tendency of erythema nodosum, pretibial
myxoedema and necrobiosis lipoidica (Fig. 14.4) to involve
The morphology (shape and pattern) of a rash is equally
important. Violaceous, polygonal, flat-topped papules, topped
by a lacy patterning (Wickham striae), are typical of lichen planus
(Fig. 14.5). The Koebner (isomorphic) phenomenon, where a
dermatosis is induced by superficial epidermal injury, results in
linear configurations (Fig. 14.6A), and occurs par excellence in
14.2 Fitzpatrick scale of skin types
• Type 1: always burns, never tans
• Type 2: usually burns, tans minimally
• Type 3: sometimes burns, usually tans
• Type 4: always tans, occasionally burns
• Type 5: tans easily, rarely burns
• Type 6: never burns, permanent deep pigmentation
Fig. 14.3 Distribution of rash. A Atopic eczema localising to the
flexural aspect of the knees. B Psoriasis involving the extensor aspect of
The physical examination • 287
psoriasis, lichen planus, viral warts and molluscum contagiosum.
Linear or angular markings (erythema or scarring) raise the
likelihood of artefactual (self-inflicted) damage to the skin. The
presence of blisters limits the diagnostic possibilities to a relatively
small number of autoimmune (such as dermatitis herpetiformis,
pemphigoid (Fig. 14.6B) and pemphigus), reactive (including
Abscess A collection of pus, often associated with signs
and symptoms of inflammation (includes boils and
Angioedema Deep swelling (oedema) of the dermis and
Atrophy Thinning of one or more layers of the skin
Blister A liquid-filled lesion (vesicles and bullae)
Bulla A large blister (>0.5 cm)
Burrow A track left by a burrowing scabies mite
Callus (callosity) A thickened area of skin that is a response to
Crust (scab) A hard, adherent surface change caused by
leakage and drying of blood, serum or pus
Cyst A fluid-filled papular lesion that fluctuates and
Erosion A superficial loss of skin, involving the epidermis;
scarring is not normally a result
Erythema Redness of the skin that blanches on pressure
Erythroderma Any inflammatory skin disease that affects >80%
Fissure A split, usually extending from the skin surface
through the epidermis to the dermis
Freckle An area of hyperpigmentation that increases in the
summer months and decreases during winter
Haematoma A swelling caused by a collection of blood
Horn A hyperkeratotic projection from the skin surface
Hyperkeratosis Thickening of the stratum corneum
Keratosis A lesion characterised by hyperkeratosis
Lentigo An area of fixed hyperpigmentation
Lichenification Thickening of the epidermis, resulting in
accentuation of skin markings; usually indicative of
Macule A flat (impalpable) colour change
Naevus A localised developmental defect (vascular,
melanocytic, epidermal or connective tissue)
Nodule A large papule (>0.5 cm)
Onycholysis Separation of the nail plate from the nail bed
Papilloma A benign growth projecting from the skin surface
Papule An elevated (palpable) lesion, arbitrarily <0.5 cm
Petechiae Pinhead-sized macular purpura
Pigmentation A change in skin colour
Plaque A papule or nodule that in cross-sectional profile is
Poikiloderma A combination of atrophy, hyperpigmentation and
Purpura Non-blanchable redness (also called petechiae)
Pustule A papular lesion containing turbid purulent material
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