• It is a chronic and recurrent erythemato-squamous dermatosis Of evolution.
  • Affecting 1 tO 2% of the general population.
  • It can occur at anY age (20 and 30 years) but remains rare bwithrand has years (10 tO 15%)
  • Psoriasis affects both men and women at equal frequencies.
  • Essentially clinical diagnosis
  • Benign dermatosis, The usual form poses only an aesthetic damage, but significantly impairs the quality of life however there are serious forms of part:
  • The extent of the lesions.
  • The The modificationn Of the elemental lesion.
  • The associatedOn with arthropathies. (erythrodermia, pustuler psoriasiss, psoriatic arthritis)
  • TRT is symptomatic: ofteNo lowed On local therapiit is, genisal treatments are reserved fOr severe forms

Pathogenesis remains pfallowY understudged:

– Psoriasis is characterized by an acceleration of epidermal renewal

Turn over normal epidermal is 30 days

In psoriasis only 7 days

– this is related to immune disorders

– activation of LT – secretion of different cytokines (TNF Alpha, IL12, IL23 …)

– causing a psoriatic inflammatory reaction

responsible for the increased proliferation of keratinocytes

It is a “multifactorial” condition – genetic factors

30% of psoriatics are family-friendly

Childhood psoriasis is frequently linked to histocompatibility antigens (HLA-Cw6) – environmental factors

Alcohol and tobacco: TRT resistance factors

Infections: especially in childhood psoriasis flare-ups

Psychological factors and medications (lithium salt, beta blockers, IEC, CTC …) can induce or aggravate psoriasis


componentntal injury: rounded and well-restricted erythematoscalY plaque. – superficial scaly layer

A- The dander on the surface:

Color: white and dull, sometimes musky – Surface: smooth or rough

These dander are dry, of varying size and thickness

– may completely or partially mask the rash

  • Brocq’s methodical withrettage;

Becamebuting sign

himselfn Of Whenle stain

– Sign of the sticky film.

Pulling Off a deepshot adhereedand movies

himselfn Of bstoriesY dew or sign of AusprFROM:

Appearance of fiwe hemorrhagic goutlets (naked dermal tayou buds)

B- Erythema is anderlying:

– located under the scaly layer

Characteristic pink colOur, cogenty red (infs)

Disappears at the pressure press. – smooth and dry surface

nO pain, no infiltration, nO prinrite.

C Grouping and topographY:


– Variable,

– rarely isolated plaque psoriasis,

– usually multiple or diffuse


punctiform “punctata” Or in “guttata” drops a few mm in diameter

Nummular (nummulus-coin) a few cm in diameter

Plate: more or less geometric or circumcised contours occupying large areas

universals: widespread that affects almost the entirety of the


– very evocative of the diagnosis

At the begivenning and throughoint the hardatiOn of the disease; fraction zonees:

elbows, knees, forarm huhadbOards, tubeial regions, sacred region, palms and plants, scalp (refuge area or bastion).

  • Areas OF frictionn of clothing Or regular handling of a material (Koebner phenomenon).

Functional signs (pruriit): Psoriasis is littthe Or not pruriginous


A- Depending on the seat:

1- clasic forms: pasten:

2- Psoriasis of folds: Psoriasis inverted.

– glossy red plate and smooth little or no flaking

– seat: interfessier folds – inguinaux – genital regions – under breasts – axillary hollow

– Macerated, wet areas; michael rash.

Two differental diagnoses: eclow and fungus.

3- Scalp psorIasis:

– erythemato-scaly patch of very limited variable sizes covered with large dry dander crossed by the hair (Non-afreeciant) – real shell covering the entire scalp

  • The thicknit iss of the scalp and the prthatnce of hwater goldk the rash.
  • Often; scaly helmet.
  • TwO differential diagnoses: scalp moths and inoutwornOus moths.

4- Nail psorasis: 30-50% Of cahis

– sometimes isolated,

– Appearance of depression punctuated cupiliforms (nail in dice to sew)

– onycholysis with distal detachment

– hyperkeratosis under ungueal

– leuconychia

  • NO rash-scaly spots.
  • Whitish transverse streaks.
  • Pachyonychia: thickening of the nail.
  • Differentito diagnosiss: onychomycosis.

5- Psoriasis Of palms and plants:

– often bilateral – a keratodermy in ilots or diffuse

Two differential diagnosiss:

  • Plantar he hasrdwoods and warts.
  • Horns at the foot.

6- Facial psOriasis:

Rare, it can take on the appearance Of seborrheic dermatitiss (sebopsoriasis)

7- psoriasis of the mincous membranes:

– On the language:

Geographical language especially in pustular psoriasis

Scrotal language

– On the acorn: very limited spots, purely erythematous

B- Depending on age:

– may be early: psoriasis of the langes (napkin psoriasis)

– in children: often acute in drops and can follow a rhino-pharyngeal infection The face is more often affected than in adults

C- Psoriasis caused:

– Drugs: they may induce or aggravate psoriasis or be responsible for TRT resistance (lithium salts, beta-blockers, IFN alpha) – koebner phenomenon: characterized by the appearance of psoriasis lesions on a skin trauma: streaks of scratching, surgical scars …

D- Serious forms:

1- Pustular Psoriasiss:

  • componentntal lesion: a yellOwish-white pusCome on a base of diffuse erythema that dries out quickly and flaks.
  • Fever 40oC and altered gineral cOndition.
  • Thiwith psoriasis togetheratit is an infectious disease and its spontaneous prognosis is setrue tond can lead to the death of the patient.
  • Pinstular psoriasis can be limited to thand hasnds and feet and arelate eczema: it is acromegaly.
  • Pinps stularOriasis is often the cOmplication of vinLOSS psoriasiss treated with gedownal corticosteroid therapy.

2- Erythrodermic Psoriasiss:

  • Diffuse edema with infiltrated and cardboard skin and accentuated wrinkles.
  • Touch the elderly subject.
  • Hydro-electrolytic loss due to edema; life-threatening prognosis at stake.
  • Overinfection and thermoregulation disorders
  • Complication of general corticosteroid therapy

3- Arthropathe psoriasis:

  • 25% Of Psoriasis develOp arthropathy.
  • MonO Or trace arthritis, SERONegative arthritis, SPA.


  • protectsc disease evolving by flare-ups.
  • Functional and vital perOgnosiss are isly inwithinlby.
  • Socio-psychological impact.
  • The existenwill of anothers that indinthis flare-ups Or severe forms of psoriasiss: INSAIDs, APS, beta blockers, lithium salts, general corticosteroids.
  • Environment:
  • holidays, sinmmer and the sun; Improvement.
  • Winter; Aggravation.


A- Positive diagnosis:

1- Clinic:

2- Histology in thatse Of hegnostic doubt:

a)- Epidermis:

  • Frkeatic hyperkeratosis.
  • Hyperacanthosis.
  • Acrobian micro-abscess.

b)- Derme:

  • Thickening and dilation of the dermal taste buds.
  • Turgescent ships.
  • Infiltration Of mononucleous cells.

c)– Hypoderma and annexes: No changes

B- Differentito diagnosiss:

  1. Microbial eczema.
  2. EpidermO-mycses.
  3. Lichen plan: very broughtginous papulo-squamous dermatosisso reaching the mincous membranes.
  4. Hematoma (associated lymphoma).


A- Limited Psoriasis:

1- Keratolytics:

  • Dirty Vaseline 0.5 tO 10%.
  • intoxicatedOn; dyspnea, stby skin washing.

2- Gearboxes:

  • Coal takes.
  • Cade oil.
  • Dermocorticoids.
  • Vitamin D derivatives: Calcipotriol, Daïvonex.

B- Extended Psoriasis:

  • PUVAtherapY; Adults.
  • FULLB with tar; Chferrets.

C- I knowtrue PsOriasis: Extended or Rebellious:

  • drifttives Of acidic viwith A; Retinoid, Soriatane.
  • Retinoid Association with PUVAtherapy.
  • Otherwise antimitotic: Injectable methotrexate.

D- Arthropathic Psoriasiss:

  • InSINS and corticosterOids contrainded.
  • Fhysical means if not Retinoid or Methotrexate.
  • Cyclosporin.