- 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 before ten 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 modification of the elemental lesion.
- The association with arthropathies. (erythrodermia, pustular psoriasis, psoriatic arthritis)
- TRT is symptomatic: often based on local therapies, general treatments are reserved for severe forms
Pathogenesis remains poorly 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
II- CLINICAL: CLASSIC FORM OF VULGAR PSORIASIS
Elemental injury: rounded and well-restricted erythemato–scaly 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 curettage;
– Bleaching sign
– Sign of candle stain
– Sign of the sticky film.
Pulling off a deep–shot adhesive film
– Sign of bloody dew or sign of AUSPITZ:
Appearance of fine hemorrhagic goutlets (naked dermal taste buds)
B- Erythema is underlying:
– 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 pruritus.
C– Grouping and topography:
– 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
– Universalis: widespread that affects almost the entirety of the
– very evocative of the diagnosis
At the beginning and throughout the duration of the disease; friction zones:
elbows, knees, forearm headboards, tibial regions, sacred region, palms and plants, scalp (refuge area or bastion).
- Areas of friction of clothing or regular handling of a material (Koebner phenomenon).
Functional signs (pruriit): Psoriasis is little or not pruriginous
III- CLINICAL FORMS:
A- Depending on the seat:
1- Clasic forms: bastion:
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 differential diagnoses: eczema 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 thickness of the scalp and the presence of hair mask the rash.
- Often; scaly helmet.
- Two differential diagnoses: scalp moths and infectious moths.
4- Nail psoriasis: 30-50% of cases
– sometimes isolated,
– Appearance of depression punctuated cupiliforms (nail in dice to sew)
– onycholysis with distal detachment
– hyperkeratosis under ungueal
- No rash-scaly spots.
- Whitish transverse streaks.
- Pachyonychia: thickening of the nail.
- Differential diagnosis: onychomycosis.
5- Psoriasis of palms and plants:
– often bilateral – a keratodermy in ilots or diffuse
Two differential diagnoses:
- Plantar hardwoods and warts.
- Horns at the foot.
6- Facial psoriasis:
Rare, it can take on the appearance of seborrheic dermatitis (sebopsoriasis)
7- psoriasis of the mucous membranes:
– On the language:
Geographical language especially in pustular psoriasis
– 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, INF alpha) – koebner phenomenon: characterized by the appearance of psoriasis lesions on a skin trauma: streaks of scratching, surgical scars …
D- Serious forms:
1- Pustular Psoriasis:
- Elemental lesion: a yellowish-white pustule on a base of diffuse erythema that dries out quickly and flaks.
- Fever 40oC and altered general condition.
- This psoriasis simulates an infectious disease and its spontaneous prognosis is severe and can lead to the death of the patient.
- Pustular psoriasis can be limited to the hands and feet and simulate eczema: it is acromegaly.
- Pustular psoriasis is often the complication of vulgar psoriasis treated with general corticosteroid therapy.
2- Erythrodermic Psoriasis:
- 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.
- Chronic disease evolving by flare-ups.
- Functional and vital prognosis are only involved.
- Socio-psychological impact.
- The existence of drugs that induce flare-ups or severe forms of psoriasis: INSAIDs, APS, beta blockers, lithium salts, general corticosteroids.
- holidays, summer and the sun; Improvement.
- Winter; Aggravation.
A- Positive diagnosis:
2- Histology in case of diagnostic doubt:
- Parakeatic hyperkeratosis.
- Acrobian micro-abscess.
- Thickening and dilation of the dermal taste buds.
- Turgescent ships.
- Infiltration of mononucleous cells.
c)– Hypoderma and annexes: No changes
B- Differential diagnosis:
- Microbial eczema.
- Lichen plan: very pruriginous papulo-squamous dermatosis also reaching the mucous membranes.
- Hematoma (associated lymphoma).
A- Limited Psoriasis:
- Dirty Vaseline 0.5 to 10%.
- Intoxication; dyspnea, stop skin washing.
- Coal tar.
- Cade oil.
- Vitamin D derivatives: Calcipotriol, Daïvonex.
B- Extended Psoriasis:
- PUVAtherapy; Adults.
- PUVB with tar; Children.
C- Severe Psoriasis: Extended or Rebellious:
- Derivatives of acidic vitamin A; Retinoid, Soriatane.
- Retinoid Association with PUVAtherapy.
- Otherwise antimitotic: Injectable methotrexate.
D- Arthropathic Psoriasis:
- InSINS and corticosteroids contrainded.
- Physical means if not Retinoid or Methotrexate.