Elementary skin lesions


Introduction :

?? The diagnosis in dermatology based, as in other medical specialties, on questioning, physical examination and additional investigations

?? The seed coat is often the mirror of internal diseases ; the discovery of cutaneous signs, easily accessible to analysis and biopsy semeiologic, may well save the patient more expensive or uncomfortable explorations

?? "elementary lesions" are skin response modes to different diseases and attacks it suffers

?? the lesion must be individualized easily enough without being confused with another injury

?? These elementary lesions are an "alphabet" that the doctor must learn to read to be able to make the diagnosis of a disease that affects the skin

?? We propose to classify basic lesions mainly : based on two criteria

  • palpable or not the lesion ;
  • the presence of alteration to the surface of the lesion.

lesions primary :

are lesions that appear de novo and reflects the initial lesion process .

A- Lesion non palpable : macule

?? This is a visible lesion but not palpable

?? It results in a localized change in skin color without any visible alteration of its surface (sans relieves)

?? size : varies usually between 5 and 20 mm

?? may result from an abnormality in serving :

  • l & rsquo; epidermis example :vitiligo
  • dermis example : petechiae
  • the epidermis and dermis example : hyperpigmentation post- inflammatory
  •  The blotches can be classified according to their color and the effects of vitropression In :

1) macules dyschromiques : who can be :

  • white example : vitiligo
  • pigmentary example : lentigo
  • eg blue-gray : Mongolian spot
  • yellow example : xanthome plan
white or achromique macula with islands of repigmentation around the hair follicles in a vitiligo.
white or achromique macula with islands of repigmentation around the hair follicles in a vitiligo.
Senile lentigines on the dorsal side of the hand.
Senile lentigines on the dorsal side of the hand.
Mongolian spot
Mongolian spot

2) erythematous macules :

?? Red blotches deserve special mention because of their semiotic peculiarities and frequency.

?? These can result from an active or passive vasodilatation (example : exanthème, cyanose) or by intravascular blood accumulation (example : angiome).

?? They then disappear for vitropression, versus purpuric macules resulting from extravascular deposits of red blood cells that persist in the vitropression.

1- erythema :

?? is a localized or diffuse redness of the skin, fading to vitropression, sustained or paroxysmal,

?? The color varies from pale pink to dark red .

?? The rash often associated diffuse flat lesions and palpable lesions papules and / or plaques thus achieving, when sudden onset, maculopapular rash .

erythema 2

erythema 1





On a :

?? L'exantheme morbiliforme : made of red blotches that tend to coalesce while respecting healthy skin intervals .

?? L’exantheme scarlatiniforme : c’is an intense redness ,diffuse, here conflue sans laisser de peau d'INTERVALLE Healthy and quin women the impression of a Granite in the tango .

erythema scarlatiniform
erythema scarlatiniform
rash morbilliform
rash morbilliform





?? roseola :it is a color of pink lesion well individualized measuring generally less 02 cm ex: syphilitic roseola .

?? L’erythrodermie : diffuse erythema, prolonged evolution, grave, affecting more than 90 % of the body surface, accompanied immediately or very quickly by desquamation.








2- La cyanose :

is a violet blue coloration of the skin with less local temperature touching the ends and mucous membranes healthy skin comes together without intervals.


3- vascular macule : red nonpalpable lesions correspond to a permanent dilation of small blood vessels of the superficial dermis and / or an excess of the number of capillaries :

?? telangiectasia: is red lesions nonpalpable corresponding to a permanent dilation of small blood vessels of the superficial dermis as small sinuous lines of a few mm emptying has vitropression.

?? La poikilodermie: it is the combination of skin atrophy and a crosslinked pigmentation and telangiectasia.

?? L’angiome plan : congenital lesion, vary in size, Chronic throughout life, dark red , very limited.

Telangiectasias resulting from dilation of superficial vessels of the dermis and disappearing at vitropression.
Telangiectasias resulting from dilation of superficial vessels of the dermis and disappearing at vitropression.
Angiome plan
Angiome plan

4- purpura : it is a permanent redness does not erasing has vitropression reflecting hemorrhage intra dermal.

?? Purpura may be limited or extended and go through different shades ranging from red to blue to green to yellow to let persist transient or lasting way a brown sequelae

petechiae : is limited purpuric lesions of small dimensions

stripes : is linear streaks purpuric +/- broad and +/- elongated

ecchymosis : Extended purpuric plate often irregular outline having various dyed .

petechial purpura
petechial purpura
Purpura in vibices
Purpura in vibices







3) macule atrophique :

it is a non-palpable lesions that can maintain normal color but become visible due to unusual skin transparency, revealing the vessels, becoming smooth and finely wrinkled thereby taking an aspect in "cigarette paper"

Blesions palpable :

?? They are noticeable when walking the fingertips parallel to the surface of the integument by exerting a varying pressure, even though they are sometimes invisible.

?? There are several types of palpable lesions that are distinguished by :

  • based on content (fluid or solid).
  • And size .
  • And their skin localization (superficial or deep).

1)  lesions solid :

a) The papule : is usually defined as a palpable lesion small, non-liquid contents.

?? Its size should not exceed 10 mm.

?? papules may be foliculaire distribution or non-follicular.

?? papules must be distinguished from other palpable lesions that are larger (plaque, nodule, tumor), located deeper (nouure), of liquid contents (vesicle, bubble) or which result primarily from a surface alteration (horn, kératose).

Multiple papules "dome", confluent in places, during a papular amylose.
Multiple papules "dome", confluent in places, during a papular amylose.
Papules grouped into "ring" during granuloma annulare.
Papules grouped into "ring" during granuloma annulare.

b) plaque :

refers to larger lesions embossed surface in height and measuring more than 1 cm


c) lichenification : is a thickening of the skin with exaggeration of its furrows, making apparent normal grid

lichenification plate providing a skin thickening with exaggeration of its furrows. Note also the presence of linear erosions due to scratching.
lichenification plate providing a skin thickening with exaggeration of its furrows. Note also the presence of linear erosions due to scratching.

d) The tuber :

?? is a palpable lesion without intradermal (with little or) relief.

?? These lesions are often chronic course or regressing tend to leave a scar

?? They are contained and movable relative to the hypodermis.


e) The nodule :

?? is a palpable mass, not liquidienne, measuring over 10 mm. the nodules are dermal seat and / or hypodermic.

f) tumor :all nodule>20mm without inflammatory character.

g) nouure : is a large nodule (more often 5 cm), hypodermic extension,

Skin nodule because of inflammatory (sarcoïdose)
Skin nodule because of inflammatory (sarcoïdose)
Nouures scattered on both legs (erythema nodosum)
Nouures scattered on both legs (erythema nodosum)

h) Gomme : as nouure when to pass the crudeness of phase due to the softening and fistula and eventually scarring.


I) vegetations :

?? Threadlike growths look, fingered or branched lobulated cauliflower-like soft consistency.

?? Frequently on mucous membranes or around body orifices.

?? The surface of the lesion is formed of a thinned epidermis and rosé.


J) Verrucocité : are the threadlike growths look, digitate or lobulated, sometimes branched cauliflower whose surface is covered with a coating horny, keratosis often grayish, thicker or thinner .

keratotic surface vegetation, définissant the verrucosité au cours d'une wrat periungual.
keratotic surface vegetation, définissant the verrucosité au cours d'une wrat periungual.




k ) Cordon : are easily palpable lesions suggests a rope or string, are linear, more or less very variable size.

l) Sillon : small tunnel in the skin that usually houses a parasite.

?? This is often millimeter lesions barely visible and / or palpable.

2) lesions from contents liquidien :

?? This is a most often palpable lesion raises the skin by forming a cavity which contains a liquid.

?? Lesions whose content is fluid are distinguished by their size and appearance of the liquid

?? Vesicle :

  • uprising circumscribed skin
  • Cut :less than 3 mm containing a clear liquid .


?? Bubbles :

  • uprising circumscribed skin .
  • Cut :more than 05mm .
  • containing a clear liquid ,sero purulent or haemorrhagic. They can be located on the skin, but also on external mucosa (mouth, conjunctival, nasal, anogenital).



1- the bubbles underepidermal : the roof is solid and can be based on normal skin, erythematous or urticarial.

2- bubbles epidermal : fragile, often spontaneously broken, then presenting as an erosion bordered by a collar.

bubbles subepidermal


?? relief lesion of a few mm or cm, content immediately purulent milky white or yellowish coloration .

Among the pustules, on distingue :

1- follicular lesion : which are acuminate by a bristle (example : folliculite)

follicular lesion

2 lesion non follicular : more planar and not acuminate General, seat intraepidermal, very superficial, sub-horny.

multiple pustules, non-follicular, on erythematous background
multiple pustules, non-follicular, on erythematous background

alterations from the surface from the skin :

1A erosion :

?? East a loss from the part superficial from the skin (l & rsquo; epidermis) that heals without scarring.

?? This is a wet lesion, suintante, overlapping secondarily crust .

  • excoriation :

?? East sometimes employee for designate a erosion secondary to trauma, often scraping.

  • A fissure

?? is a linear erosion.


2 A ulceration :

?? deeper, affects the epidermis and dermis, if it heals leave a scar, can be covered with a fibrin coating, a sérosanglante crust or black plate.

?? an ulcer : loss of substance without chronic tendency to spontaneous healing.

  • the bedsores: dulcers are pressure points.

3 A fistula :

?? is a skin sluices, variable depth, which corresponds to an abnormal communication of a deep structure to the surface of the skin.

dental fistula
dental fistula

4- Les squames :

?? I know define as of the strips from cell corneas at the skin surface.

?? They are little adherent and off easily.

?? They are visible and appear spontaneously after scraping with a foam board curette.

?? Next the online and the aspect des squames, on distingue :

  • squames ichtyosiformes : size and polygonal shape (fish scales) ex :hereditary ichthyosis.
Scales ichtyosiforme
Scales ichtyosiforme
  • squames pityriasiformes : petites squames fines, some members, whitish and floury. (ex pityriasis versicolore).
  • squames scarlitiniformes : in large pieces (former scarlatine)
  • Squames psoriasiformes:   white, bright, thick, wide and adherent ; progressive stripping shows a crumbling slats (psoriasis ).
  • squames in « collar » : fines, adherent to the center but not on the periphery, covering an inflammatory lesion.
Scarlatiniforme, Pytiriasiforme, psoriasiforme, in flange
Scarlatiniforme, Pytiriasiforme, psoriasiforme, in flange


?? a superficial drying of exudate, a secretion, necrosis or dermal hemorrhage.

?? The evolutionary stage of various primary lesions: bubbles, vesicles or pustules.


6- A kératose :

?? thickening cornea wider than thick,. very adherent and hard on palpation

7- A horn :

?? keratosis thicker and taller than it is wide .


8– The gangrene :

A blackish tissue necrosis , tissue non-viable skin which tends to eliminate , cold to the touch.


9- Scar :

?? Represents the result of a repair process involving the dermis especially after loss of substance or skin inflammation.


Modifications from the consistency skin :

?? Finally, some lesions are mainly due to a change in the consistency of the skin that becomes too much or not flexible enough.

?? These lesions are especially apparent on palpation.

1)L’atrophy cutaneous :

?? is defined as the reduction or loss of all or part of the components of the skin (epidermis, dermis, hypodermis or

?? of them, even three compartments).

?? It appears as a thinning of the body wall which ride the superficial nip, losing its elasticity, its relief and taking a look smooth and pearly.


2)- Sclerosis :

Visible and especially palpable, characterized by thickening and loss of’skin elasticity, due to condensation of the components of the dermis.


3)anetoderma :

Depression at the palpation . Fat à l'Inspection .


Way allowing affirm the diagnostic :

  1. vitro pression.
  2. Wood light.
  3. application of some substance.
  4. physical maneuver.
  5. scratching by a blunt dissector.
  6. dermatological magnifier .
  7. dermatoscope.







Conclusion :

  • and dermatology, more than in any other medical discipline, physical examination is the defining element of the diagnostic process.
  • A perfect knowledge of dermatological symptomatology is essential.
  • The dermatological examination should identify the basic or lesions, recognize any configuration and / or arrangement remarkable and appreciate the distribution of lesions.
  • This approach can diagnose many diseases, without recourse to additional examinations, a rare privilege in our time.

Prepared by: Dr bouhila – Framed by: Dr laroum

Faculty of Constantine