2. Introduction
A systematic approach enables most diagnoses to be
made
Dermatology is no different from other things but
there are some special points.
3. Although history is important, in
dermatology, the diagnosis is most
frequently made based on the
objective physical characteristics.
Therefore, careful physical
examination of the skin is
paramount in dermatologic
diagnosis.
4. Typically, most skin diseases produce or
present with lesions with more or less
distinct characteristics.
may be uniform or diverse
in size, shape, and color,
and may be in different
stages of evolution or
involution.
5. History
The patient's age, health,
occupation, hobbies, living
conditions
The onset, duration, and course of
the disease
Response to previous
treatment
The family history of
similar disorders and
other related diseases
Complete drug history
6. History (cont’d)
Other illnesses
Travel abroad and in the country
The patient's environment at home and at work
Seasonal occurrences and recurrences of the
disease
The temperature, humidity, and weather
exposure of the patient
Habitation in certain parts of the world or
country predisposes to distinctive diseases.
Sexual orientation and practices may be
relevant in some diseases.
7. Examination
Should be conducted in
a well-lit room.
Natural sunlight is
the ideal illumination.
A magnifying lens is of inestimable value in examining small lesions.
The complete skin examination includes examination of Hair, Nails, and
Oral/genital Mucosa.
8. Palpation
Palpation is an essential part of the physical
examination of lesions.
Does the lesion blanch on pressure? If not, it
may be purpuric.
Is it fluctuant? If so, it may have free fluid in it.
Is it cold or hot?
If there is a nodule or tumor, does it sink
through a ring into the panniculus, like a
neurofibroma?
Is it hard enough for calcification to be
suspected, or merely very firm, like a keloid or
dermatofibroma? Or brawny, like scleredema?
9. Palpation
It may be necessary to
palpate the lesion for
firmness and fluctuation.
Rubbing will elucidate the
nature of scales.
Pigmented lesions,
especially in infants,
should be rubbed in an
attempt to elicit Darier's
sign (whealing), as seen in
urticaria pigmentosa.
11. Cutaneous signs
primary lesions:
Identification of such lesions is the most important
aspect of the dermatologic physical examination.
secondary lesions:
modified by regression, trauma, or other extraneous
factors
26. Nodules:
Morphologically similar to papules, but they are larger than 1 cm in
diameter.
They most frequently are centered in the dermis or subcutaneous fat.
27.
28.
29. Tumors:
soft or firm and freely movable or fixed
masses of various sizes and shapes (but in
general greater than 2 cm in diameter.
elevated or deep seated, and in some
instances are pedunculated (fibromas).
A tendency to be rounded
Their consistency depends on the
constituents of the lesion.
32. Vesicles (Blisters):
Circumscribed, fluid-containing, epidermal elevations
Less than 1 cm
Primarily filled with clear fluid
May be pale or yellow from serous exudate, or red from serum mixed
with blood
36. Bullae:
rounded or irregularly shaped blisters
Containing serous or seropurulent fluid.
They differ from vesicles only in size, being larger than 1 cm.
38. Bullae may be located :
superficially in the epidermis:
so that their walls are flaccid and thin
subject to rupture spontaneously or from slight
injury.
may dry to form a thin crust; or the broken bleb
may leave a raw and moist base
OR
Subepidermal:
they are tense.
40. Nikolsky's sign:
The diagnostic maneuver of putting lateral pressure on unblistered
skin in a bullous eruption and having the epithelium shear off.
Asboe-Hansen's sign:
The extension of a blister to adjacent unblistered skin when pressure
is put on the top of the blister.
42. Pustules:
small elevations of the skin containing purulent
material (usually necrotic inflammatory cells)
Less than 1 cm
They are similar to vesicles in shape and usually
have an inflammatory areola.
They are usually white or yellow centrally, but
may be red if they also contain blood.
50. Scales (Exfoliation):
Accumulation of stratum corneum due to
proliferation or delayed desquamation
hyperkeratosis
Vary in size
Some being fine, delicate and branny
Coarser, as in eczema and ichthyosis
Still others are stratified, as in Psoriasis.
Occasionally, they have a silvery sheen from trapping
of air between their layers.
55. Crusts (Scabs):
Crusts are dried serum, pus, or blood.
Usually mixed with epithelial and sometimes bacterial debris.
Vary greatly in size, thickness, shape, and color, according to their
origin, composition, and volume.
58. Excoriations and Abrasions (Scratch Marks)
An excoriation is a punctate or linear abrasion
produced by mechanical means.
Usually involving only the epidermis but not
uncommonly reaching the papillary layer of the
dermis.
Excoriations are caused by scratching with the
fingernails in an effort to relieve itching in a variety
of diseases.
If the skin damage is the result of mechanical trauma
or constant friction, the term abrasion may be used.
60. Fissures (Cracks, Clefts):
A fissure is a linear cleft through the epidermis or into
the dermis.
Results from marked drying,skin thickening and loss of
elasticity
When the skin is dry, exposure to cold, wind, water,
and cleaning products (soap, detergents) may produce a
stinging, burning sensation, indicating microscopic
fissuring is present.
When fissuring is present, pain is often produced by
movement of the parts, which opens or deepens the
fissures or forms new ones.
66. Ulcers
Ulcers are rounded or irregularly shaped excavations that result from
complete loss of the epidermis plus some portion of the dermis.
heal with scarring
70. Scars:
Scars are composed of new connective tissue
that replaced lost substance in the dermis or
deeper parts as a result of injury or disease, as
part of the normal reparative process.
Scars may:
be thin and atrophic
OR
The fibrous elements may develop into neoplastic
overgrowths, as in keloids.
88. Diascopy
Diascopy: pressing a glass slide onto the skin
compresses blood out of small vessels , to allow
evaluation of other colors:
granulomatous nodules: apple jelly
nodules
(translucent brown)
nevus anemicus vs. vitiligo
