introducedon :

  • Psoriasis is an inflammatory dermatosis skin, characterized by erythematous, scaly chronic lesions
  • It is common (2% Population), it occurs at any age, especially among young adults (between 20 and 30 years)
  • It is a benign skin disease but significantly alters the quality of life
  • The diagnosis is mainly clinical
  • There are serious forms : erythroderma, psoriatic arthritis, pustular psoriasis
  • Its pathophysiological mechanisms are not well understood
  • Treatment is symptomatic, often based on local treatment. The general treatments, used exceptionally, are reserved for severe forms
  • aggravating factors : stress, infection, drug

Pathogenius :

  • Psoriasis is characterized by accelerated epidermal renewal, indeed, the epidermal turn over (which is normally 30 days) is only 7 days in psoriasis, This is associated with immune disorders (Activation of LT and secretion of various cytokines : TNFα, IL12, IL23 ...) causing psoriatic inflammatory response responsible for the increased proliferation of keratinocytes
  • It is a multifactorial disease :

Postman genetic : 30% psoriatic are family, when the disease begins in childhood, it is frequently linked to histocompatibility antigens (HLA Cw6)

factors environment :

  • The alcohol and tobacco are treatment resistance factors
  • Infections are highlighted especially in outbreaks of psoriasis in children
  • Psychological factors and drugs (lithium salts, β-blockers, IEC…) may induce or aggravate psoriasis

CLinique :

  • Form classical of psoriasis vulgar :

Lesion elementary : it is a scaly erythematous spot

  • Layer squameuse superficial : whitish and dull color, smooth or rough surface, slightly raised relative to the adjacent healthy skin. These scales are dry,  size and of varying thickness,  may mask completely or partially erythema. The methodical scratching Brocq reveals :

Sign from whitening : the first shots drain cleaners remove the surface layers brittle and the surface becomes bright white

Sign from the task from candle : the deep layers are more consistent, have a micaceous appearance

Sign from the film peelable : tearing of a thin adherent film at deep plane

Sign  the bloody dew (sign of Auspitz) : is the appearance of fine droplets haemorrhagic, reflecting the exposure of the dermal papillae

  • Task  erythematous :  underneath the squamous layer,   characteristic pink color, rouge congestif (the lower limbs), very limited, smooth and dry, flexible, disappears at the vitropression

Group and topography :

  • Name : rarely isolated psoriasis plaque, most of the time, multiple diffuse or
  • Dimensions :

✓ In point "punctata" ou en gouttes "guttata" de quelques millimètres de diamètre, it is an eruptive psoriasis of the child, sometimes preceded by an infectious episode ENT

✓ Nummulaire (nummulus = coin) a few centimeters in diameter

✓ In plate, contours more or less geometric or vine

✓ Universalis : widespread, that affects almost all integuments

  • Topography : highly suggestive of the diagnosis (at the bony prominences), well qu'ubiquitaire, often based on exposed to trauma (elbows, ulnar side of the forearm, knees, pretibial regions, lumbosacral regions, scalp, nails)

signs functional (pruritus) : in general, Psoriasis is little or no itching

  • shapes clinics special :

shapes topographical :

  • Psoriasis  of  please  haired :  it sends either erythematous lesions sclerosis- squameuses (limited well, covered wide dry scales, through which the hair, without alopecia) is a real shell covering the entire scalp
  • Psoriasis of the more (psoriasis reversed) : is a continuous plate, rouge, smooth, glossy, little or no scaly, seat at the fold inter infragluteal, inguinal, genital area, Submammary, axilla ...
  • Psoriasis of face : rare, it may take the appearance of seborrheic dermatitis (sebopsoriasis)
  • Psoriasis palmoplantaire : often bilateral, it can realize keratodermia islets or diffuse
  • Psoriasis of the nails : 30-50% cases of psoriasis, sometimes isolated, aspect of cup-shaped depressions punctuated (nails "thimble"), onycholysis with distal abruption, subungual hyperkeratosis, leuconychie
  • Psoriasis of the mucous :

Sure the gland : although limited spots, purely erythematous

Sure the language : geographic tongue especially pustular psoriasis, langue scrotale

Psoriasis from l & rsquo; child : Psoriasis can be early nappies = "napkin psoriasis', in children,  often acute,  drops and may follow a streptococcal infection nasopharyngeal. The face is usually achieved in adults

Psoriasis caused :

  • pharmaceuticals : they can induce or worsen psoriasis or be responsible for resistance to treatment (lithium salts, β-blockers, INFα)
  • Phenomenon from Koebner : characterized by the appearance of psoriatic lesions on a skin trauma : scraping ridges, surgical scars or post-traumatic

shapes graves :

  • Psoriasis erythrodermic : Psoriasis generalized to more 90% integument, with abundant desquamation,  erythroderma may be caused by corticosteroids, it can be complicated by secondary infection, thermoregulation disorders and hydroelectric abnormalities and should cause hospitalization
  • Psoriasis  pustular :  it is pustulosis amicrobial,  it can appear immediately or on a known psoriasis can be triggered by various drugs (especially corticosteroids). it distinguish :

Psoriasis  pustular  localized  palmoplantaire :  relapsing,  functional disability is often important

Psoriasis pustular widespread (de von Zumbusch) : sudden onset with an impaired general condition, fever and red-sharp closets that are covered with pustules that can coalesce into large sheets

  • Psoriasis arthropathique : concerns about 20% psoriatic, and performs various clinical pictures

✓ Arthralgies, mono- or trace arthritis or close to rheumatoid arthritis arthritis but with, impairment of distal interphalangeal and negative rheumatoid factor

✓ axial Psoriatic arthritis with vertebral involvement and sacroiliac neighboring ankylosing spondylitis

Evolution / Complications :

  • Psoriasis is a chronic disease that progresses in spurts whose duration is variable and whose occurrence is unpredictable. Each thrust, there is recurrence or extension of old plates as new items may appear
  • During remissions, the blanched spot and may disappear completely, sometimes leaving scars or pigmented Achromic. Remissions are more frequent in summer season (beneficial effect UV)
  • Complications :

minor : surinfection, eczematisation, lichenification

major : erythrodermic psoriasis, pustular and arthropathy

Diagnostic :

  • Diagnostic positive :  is easy,  essentially clinical :  chronic erythematous scaly dermatitis (push / remission) and location of lesions in areas bastions. If in doubt -> skin biopsy with histological study :

Anomalies epidermal :

  • hyperkeratosis with parakératose : thickening of the corneocytes which retain the core
  • Microabscesses from Munro-Sabouraud : epidermal polynuclear infiltrates
  • Layer grainy decreased or absent
  • Hyperacanthose : excessive keratinocyte proliferation

Anomalies   dermal :   papillomatosis (elongated dermal papillae)   and inflammatory infiltrate (CD4), thick basal membrane with capillary highly developed in the papillae

  • Diagnosistic differential :  he poses with numerous erythematous, scaly dermatitis of chronic evolution, we will quote the : Rose Pityriasis Rosea, seborrheic dermatitis, pityriasis rubra pilaire, mycosis fongoïde, chronic eczema ...

Traitement :

  • Goals : obtain a transient disappearance more or less complete injuries (no cure)
  • arms therapeutic :

treatments local :

  • Dermocorticoïdes : they are used in ointment (dry lesions), creams are reserved to folds and scalp lotions. Their side effects are numerous and it is recommended to perform the limited duration of treatment and monitor the quantities used (number of tubes)
  • Calcipotriol (Daivonex® : derivative of vitamin D) : It is available in ointment, cream and lotion,  its activity is equivalent to that of corticosteroids (antiproliferative and anti-inflammatory)

✓ Use 2 Applications / day without exceeding 100 g / week to avoid the risk of hypercalcaemia

✓ The irritative phenomena occur in 20% cases, especially in applications on face

✓ The Calcipotriol corticosteroid-local association is very effective (Daivobet® : Daivonex + Betamethasone)

Cons-indications : pregnancy, renal failure, Patients on vitamin D or calcium

  • Other treatments topical :

keratolytic (salicylic acid at a concentration of 2-5% in a fatty excipient "Vaseline", urea 10-20%) : are very useful in hyperkeratotic lesions

Bains and emollients : are useful for stripping lesions

products at base from tar : oil of cade (wood tar), as caditar lotion, to put in bath or shampoo water

retinoids topical (Tazarotène) : have an important irritative effect, reserved for very limited psoriasis (< 10% of the body surface)

treatments general :

  • acitretin (retinoid, derivative of vitamin A : Soriatane® or Néotigason®) : in the form of capsules 10 and 25 mg, prescribed dose of 0.3-0.5 mg/kg/j

Effects secondary : are dose-dependent : Skin and mucosal dryness (mandatory cheilitis), hepatotoxicity (reversible upon discontinuation), hypercholesterolemia,   hypertriglycéridémie,   teratogenic risk (against- says his administration during pregnancy and involves in any woman of childbearing period achieving a pregnancy test before treatment and the use of reliable contraception before treatment started, continued during treatment and for 2 years after shutdown)

✓ re-PUVA : Retinoids association and PUVA

  • methotrexate : cytostatic most used

Form : tablets 2.5 mg and injectable ampoule 10, 25 and 50 mg (IM or subcutaneous)

Dose : 15-25 mg / week, the effect starts from the 8th week

Effects secondary : in particular blood and liver, require strict monitoring

  • cyclosporin : powerful immunosuppressive therapy, very effective, but with significant nephrotoxicity risk during prolonged treatment. The starting dose is 2.5 mg/kg/j, it can be increased subject to a good clinical tolerance (HTA) and biological (creatinine) up & rsquo; to 5 mg/kg/j

Phototherapy :

  • PUVA therapy (photo-chemotherapy) : comprising administering 2h before irradiation with UVA (320-400  nm)  a photosensitizing psoralen (8-methoxypsoralen-Méladinine®) tablet

Effects secondary : erythema early, acceleration of skin aging and skin cancer induction or cataracts)

✓ Used to reason 3 sessions per week and does not exceed 100-150 j / cm2 for a cure 30 sessions per year 100 sessions in life

  • Phototherapy UVB (290-320 nm) : mainly used in the form of UVB narrow spectrum (TL-01 : 311 nm), phototherapy leads in 80% cases remission of lesions 4 at 6 weeks of treatment
  • Thalassotherapy / Crenotherapy : bathing seas associated with sun exposure, spa treatments are a good adjuvant therapy

biotherapy : these drugs are biological molecules (Derived from Biotechnology), used to block or inhibit specific steps in the pathogenesis of psoriasis, are referred to anti-TNF [etanercept (Enbrel®), Infliximab (Remicade®), Adalimumab (Humira®)] or referred lyphocytaire T by inhibition of binding LFA-1-ICAM-1 [Efalizumab (Raptiva®)]. Their indication is for chess or previous systemic treatments against-indications

  • Indications : they depend, Firstly, the type of psoriasis, d & rsquo; other, the patient himself and his quality of life

shapes localized : local treatment is sufficient

shapes  very  extended :  the processing includes :  phototherapy and / or retinoids or methotrexate or cyclosporine

shapes clinics special :

  • Psoriasis pustular : acitretin
  • Psoriasis erythrodermic : hospitalization + local treatment + methotrexate or acitretin
  • Rheumatism psoriasique invalidating : Methotrexate or cyclosporine

Conclusion :

Psoriasis is a common disease, mild but can be severe, not only because of its complications, but also because of its impact on the quality of life of the patient. If the treatments used here are merely symptomatic,   hopes go,   today,   by targeted immunomodulatory treatments on the steps of the pathophysiology of psoriasis