Psoriasis

Review Status: Internally reviewed


Figures:

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Psoriasis vulgaris1-1 Psoriasis vulgaris1-2
 

Click on the small images to view in more detail.

Figure 1.Psoriasis of the scalp
 
Figure 2a.Psoriasis of the scalp
 
Figure 2b.Psoriasis of the scalp
 
Figure 3.Psoriasis : Trunk
 
Figure 4a.Psoriasis: Trunk
 
Figure 4b.Psoriasis: Trunk
 
Figure 4c.Psoriasis: Trunk
 
Figure 5a.Psoriasis: Back
 
Figure 5b.Psoriasis: Back
 
Figure 6a.Psoriasis: Back
 
Figure 6b.Psoriasis: Back
 
Figure 6c.Psoriasis: Back
 
Figure 7a.Psoriasis: Back
 
Figure 7b.Psoriasis: Back
 
Figure 7c.Psoriasis: Back
 
Figure 8.Psoriasis: Hand
 
Figure 9a.Psoriasis: Finger
 
Figure 9b.Psoriasis: Finger
 
Figure 9c.Psoriasis: Finger
 
Figure 10a.Psoriasis: Thigh and Knee
 
Figure 10b.Psoriasis: Thigh, posterior view
 
Figure 11.Psoriasis: Knee
 
Figure 12a.Psoriasis: Ankle, anterior view
 
Figure 12b.Psoriasis: Ankle, anterior view
 
Figure 12c.Psoriasis: Ankle, anterior view

 

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Definition:

 

Incidence and prevalence:

1.Racial and ethnic variations:

--1~1.4%in USA
--1.43~2.9%in North Europe
--0%in Latin American Indian
In Singapore, India, Chinese and Malays Age of onset:
--early at 16~22 years
--later at 57~60 years
  • Patients with a family history of psoriasis tend to have an earlier age of onset.

  • Familial tendency for psoriasis:

  •  

    Psoriasis in parents

    psoriasis in?

    siblings %

    Nil

    One

    Both

    7.8

    16.4

    50

  • Sex ratio:
     

    Etiology and pathogenesis:

    Genetic predisposition


     

    Provocation and exacerbation:

    Trauma:

    Infection:

    3.Endocrine factors:

    4.Climate (sunlight / temperature):

    5.Metabolic factors:

    6.Drugs:

    7.Psychogenic factors:

    8.Alcohol:

    9.Acquired immunodeficiency syndrome (AIDS):


    Pathogenesis:

    1.Hyper-epidermopoiesis, rapid DNA synthesis:

    --decrease cAMP, increase cGMP or cGMP/cAMP ratio.
    --certain regulatory subunits (RI and RII respectively) of cAMP-dependent protein kinases I and II in fibroblasts from psoriatic versus nornal subjects.
  • Calmodulin:?Increased biologically active or immunoreative calmodulin (low calcium) has been found in samples from lesional psoriasis skin by several groups.
  • Growth factors:
  • --increase TGF-α, EGF receptor, IL-6
    --there is shortening of the epidermal germinative cell cycle, an increase in the number of cells in the proliferative pool, and marked shortening of the epidermal turnover time in psoriatic lesions.
  • Proto-oncogenes:
  • --The increased expression in psoriatic lesional extracts of RNA for the proto-oncogenes Ki-ras, myc, fos, and abl has been reported.

    2.Metabolic:

    --Arachidonic cascade :LTB4 elicits the formation of intra-epidermal neutrophil microabsxesses.
  • Polyamines:
  • --It may induce epidermal proliferation in vivo, and the activity of ornithine decarboxylase (ODC), the rate-limiting enzyme in the synthesis of the polyamines, is increased by proliferative stimuli such as the tumor-promoting phorbol ester, UVB irradiation and hair plucking.
  • Proteinases:
  • --Some proteolytic enzymes such as plasminogen activator, may play a role in cellular activation, division and escape from contact inhibition.
  • Phosphatidylinositol:
  • --Phosphatidylinositol (PI) specific phospholipase C activity was found to be elevated in psoriatic lesional samples.
    --PIP2 =>DAG+IP3
    intracellular calcium release
    activation of PKC
    --PKC activity has been reported to be significantly decreased in psoriatic skin.

    3.Immunological mechanisms:

    Activated T-cell expressing surface HLA-DR molecules and IL-2 receptors.
    Lymphocytes attracted by locally produced chemotactic factors may release γ-interferon which in turn may induce the expression of HLA-DR and ICAM-1 on keratinocytes.=>mononuclear cells bind to keratinocyte=>cytokine release and result cellular activation

    4.Basic research:


    Histopathology:


    Clinical features:
    1. Modes of onset:
    2. Particular clinical signs:
    3. The morphology of the common chronic stable plaque (psoriasis vulgaris, nummular psoriasis)

    Clinical variants:
    1. Guttate psoriasis:

    --nature of the scaling

    --general distribution

    --preceding infection

  • D/D: multiple small scaling:
  • --psoriasiform drug eruption
     
    --secondary syphilis
     
    --pityriasis rosea
     
    2. Rupioid, elephantine and ostraceous psoriasis: Plaques associated with gross hyperkeratosis.
     
    3. Erythrodermic psoriasis:

    Type 1: Extensive chronic plaque psoriasis

    --Erythroderma may occur as initial manifestation of psoriasis, or gradually or suddenly developed in a pre-existed psoriasis
    --May follow sensitivity / irritation to topical reaction
    --Widespread of follicular lesions during regression may indicating an impending relapse

    Type 2: Unstable psoriasis

    --May occurred at any time, unexpected
    --Frequently in arthropathic type, or general pustular psoriasis, induced by infection, hypocalcemia, tar or corticosteroids.
    --Frequent relapse is the feature
    --The patient is febril and ill, the course is often tumultuous or prolonged, and there is an appreciable mortality.
    --Severe itching
  • Metabolic complications of erythroderma:
  • --Universal inflammation as exfoliative dermatitis may induce the following:

    Modification by site:
    1. Scalp:

    2. Penis:

    3. Flexural (inverse) psoriasis:

    4. Hands and feet:

    5. Nail:


    Atypical forms:
    1. Linear and zonal lesions
    2. Seborrhoeic psoriasis
    3. Mucosal lesions
    4. Ocular lesions

    Associations:
    1. Other skin diseases:
  • seborrheic dermatitis
  • lichen simplex l lichen planus
  • pemphigoid
  • pemphigus
  • neurofibromatosis
  • actinic reticuloid
  • P-J syndrome
  • vitiligo
  • LE
  • viral warts
  • 2. Arthritis
    3. Gout
    4. Hypocalcemia
    5. Intestinal disease and malabsorption
    6. Cardiovascular disease

    Complications:
    1. Infection
    2. Arthritis
    3. Alcoholism
    4. Nephritis and renal failure
    5. Hepatic failure
    6. Apical pulmonary fibrosis
    7. Amyloidosis

    Differential diagnosis:
    1. Seborrheic dermatitis
    2. Eczema
    3. Lichen planus
    4. Lichen simplex
    5. Pityriasis lichenoides chronica
    6. Candidiasis
    7. Tinea cruris
    8. Pityriasis rubra pilaris
    9. Secondary syphilis
    10. Porokeratosis
    11. Bowen's and Paget's disease
    12. Penile erythroplasia
    13. Erythema annulare centrifugum
    14. The annular migratory necrolytic erythema associated with carcinoma of the pancreas
    15. Subcorneal pustular dermatosis
    16. Psoriasiform drug eruptions
    17. Parakeratosis pustulosa

    Course and prognosis:
    1. Guttate attacks carry a better prognosis than the others.
    2. An early onset and a family history of the disease appear to worsen the prognosis.

    Relapse:
    1. Relapse is the rule, however completely the lesions are treated and by whatever method.
    2. Severe cases can be maintained in prolonged remission by the use of MTX, PUVA or cyclosporin.

    Management:
  • Dithranol (anthralin):
    • Tar bath => suberythema UVB => dithranol paste (combine therapy is better than single therapy)
    • Dithranol past is not suitable for the head and neck, flexures or genitalia, where it is liable to spread and is too irritant. Short contact therapy (10 min daily) may be effective and less irritant.
    • The drug has the great virtue of lacking systemic toxicity.
    • Leaving deep brown staining.
    • Side-effect: folliculitis
  • Corticosteroids:
    • Choose to use on face and neck, flexures and genitalia. They are also used in unstable, erythrodermic and generalized pustular psoriasis in preference to tar or dithranol.
    • The merits are ease of application and removal, lack of irritancy and the absence of staining of skin or linen.
    • The hazards: topical steroids under occlusion do have a limited place in the management of recalcitrant psoriasis of the scalp, hands, feet and other areas.
    • Plasma cortisol levels are easily suppressed by the most potent preparations or high doses.
    • CPotent ones are likely to be needed on the scalp and knuckles particularly. onversely, the flexures and inner thighs need much weaker products.
  • # Intralesional corticosteroid therapy:
    Triamcinolone hexacetonide or triamcinolone acetonide can be infiltrated intradermally into localized psoriasis lesions by needle injection. It is used in troublesome small, resistant lesions on the backs of hands, especially the knuckles, intensely pruritic small plaques or lichenoid lesions.
  • Treatment of the scalp:
    • Tar-containing shampoos => cream formulations of dithranol => if fail, corticosteroid scalp lotion or gels should be drenched overnight with a coconut oil based tar and salicylic acid pomade which is shampooed out once or even twice daily.
  • Topical or intralesional cytostatic therapy:
    • Mechlorethamine
    • Thiotepa
    • Fluorouracil
    • Alkylating agent lomustine
    • Hydroxyurea
    • Topical MTX
  • Dialysis and related procedures:

  • The clearing of incidental psoriasis during hemodialysis for uremia was reported in 1976. Dialysis could favorably influence psoriasis in patients with normal renal function.
  • Occlusive dressing alone:
    • Prolonged occlusion with various tape products including Band-Acid.
    • Prolonged application of the adhesive hydrocolloid occlusive dressing.
    • Side-effects: hyperpigmentation, pain on removal of dressings, Koebner response or offensive odor.
    • It is the management of limited psoriasis.
  • Phototherapy:
    • Goeckerman first thoroughly documented the ability of crude coal tar applications followed by exposure to UV radiation to clear psoriasis.
    • Continued maintenance UVB therapy after initial clearance with UVB significantly increased the duration of disease control. An average of six treatments per month.
    • Selective UVB phototherapy (SUP) was introduced in Europe using UV sources with peak effective output in the 300~320 nm range. The excluded shorter wavelengths are also those most capable of causing DNA damage so the carcinogenic hazard may be reduced.
    • Low intensity SUP (LISUP) -home use
    • Fluorescent lamps with negligible UVC emission
    • In relation to possible carcinogenic hazards.
    • Side effects: therapeutic doses of UVB impair delayed hypersensitivity responses to dinitrochlorobenzene and mechlorethamine and may increase urinary excretion of mutagens. Prevalence of senile cataract is correlated with climatic UV exposure.
    • Very large doses of UVA alone may improve paoriasis and enhancement of UVB responses by UVA has been claimed.
    • UVB therapy is valuable for discoid psoriasis and may be especially valuable in guttate and seborrheic patterns.

    2. Systemic therapy

  • Corticosteroids:
    • The fluorinated forms such as triamcinolone and betamethasone have more effect on psoriasis than prednisolone.
    • Withdrawal the drug will induce psoriasis to relapseor may rebound. The rebound may take the form of widespread amall-patterned eruprive psoriasis often involving the face and backs of hands.
    • Systemic steroids should not be used in the routine care of psoriasis.
  • Methotrexate:
    • Orally, intramuscularly or intravenously.
    • Mechanism:
  • --competitive inhibition of dihydrofolate reductases, exerting a stronge antimitotic action on the epidermis.
    --inhibits PMN chemotaxis
  • MTX may be given as a single weekly oral dose, occasionally fortnightly.
  • During or after therapy, the renal, hepatic and marrow function tests are very important.
  • Contraindications:
  • --anemia, thrombocytopenia and leucopenia, active infection, peptic ulceration, ulcerative colitis, alcoholism, immunodeficiency, pregnancy, lactation and an unreliable patient.
  • Toxic effects:

  • --transient anorexia, nausea and dyspeptic pain.
    --bursting headaches
    --burning sensations in the psoriasis plaques --on the marrow: leucopenia, thrombocytopenia, folate-deficient megaloblastic anemia.
    --modest thrombocytopenia, low to normal WBC count
    --hetapotoxic, causing fibrosis and cirrhosis
    --oligospermia in men
    --abortifacient and teratogenic in early pregnancy
  • Risk factors:
  • --liver disease
    --impaired renal function
    --DM
    --obesity
    --increased age
  • It is particularly valuable in the chronic erythrodermic and generalized pustular forms.
  • In the event of accidental overdosage or unexpected acute toxicity, folinic acid should be given intramuscularly in full dosage.
  • Combined with:
  • --UVB
    --PUVA
    --folinic acid
    --etretinate
    --colchicine
    in order to reduce dosage and toxicity of each modality.
  • Hydroxyurea:
    • It blocks the conversion of ribonualeotides to deoxyribonucleotides by interfering with the enzyme ribonucleosidediphosphate reductase.
    • Marrow toxicity.
    • Less effective than MTX.
    • Indication: patients needing systemic treatment and who are resistant to MTX or develop side-effect.
    • Virtue: less frequent cause of anorexia, nausea and hepatotoxicity.
    • Side-effect:
  • --fall in hemoglobin
    --macrocytosis
    --cutaneous vasculitis
    --diffuse hyperpigmentation
    --actinic psoriasis
    --alopecia
    --psychological effcts
  • Razoxane:
    • It affects only cells in the mitotic cycle, acting in the late premitotic and mitotic phases. It is capable of normalizing the vasculature of certain proliferating tumors. Initial response is rapid and optimal response may take 2 to 3 months.
    • Toxicity:
  • --bone marrow toxicity (microcytotic anemia)
    --GI intolerance
    --hair loss
    --leg ulceration
    --hepatotoxicity
    --association with AML, SCC, multiple BCC, B-cell lymphoma
  • Thioguanine:
    • Bone marrow toxicity
  • Retinoids:
    • Vit. A effects on epithelial differentiation and the toxicity of hypervitaminosis A is well known. Dificiency causes cutaneous hyperkeratosis and squamous metaplasia of mucous membranes.

  • # Etretinate:
    --psoriasis vulgaris
    --pustular psoriasis
    --erythrodermic psoriasis
    --exfoliative and plaque psoriasis
  • Psoriasis vulgaris may be less responsive and is often combine with :
  • --etretinate and long-term MTX
    --corticosteroid cream
    --dithranol
    --tar
    --selective UVB phototherapy (SUP)
    --PUVA
  • Side-effect:
  • --lipophilic and progressively accumulates in the subcutis
    --teratogenic
    --hypertriglyceridemia
    --radiographic spinal changes
    --dryness of the lips, nose, eyes, mouth, throat or vagina
    --painful exfoliative cheilitis, urethritis, balanitis, gingivitis, peeling of the finger-tips and corneal ulceration.
    --rhagades, palmoplantar desquamation, burning sensations in the skin.
    --joint stiffness and synovitis
    --night blindness
  • Etretinate is very valuable in generalized pustular psoriasis.
  • Contra-indications:
  • --active liver disease
    --pre-existing hyperlipidemia
    # Isotretinoin (13-cis-retinoic acid):
    # Acitretin (formerly etretin):
  • Photochemotherapy:
     
    Definition:
  • Successful use of oral 8-methoxypsoralen (8-MOP) and UVA led to intense interest and the coining of the terms "photochemotherapy" and "PUVA".
  • Methodology:
  • --It is arbitrary.
    --Liquid form produce higher, earlier peak levels of drug in the plasma and more reproducible plasma concentrations.
    --Absorption being delayed and reduced by a fat-rich meal.
    --Treatment is given two to four times weekly.
  • Eye protection
  • Patient selection:
  • --Contra-indications: renal, hepatic or severe cardiovascular disease, cataract formation, pregnancy, children under 18 years, or pre-existing light-aggravated disease such as SLE or porphyria.
  • PUVA should only be considered as a primary treatment in those patients over 55 years where psoriasis covers at least 20%of the body surface, and who cannot be controlled by conventional topical therapy.
  • Results:
  • --excellent in discoid psoriasis vulgaris.
    --PUVA is also of value in generalized pustular psoriasis, erythrodermic psoriasis, chronic palmoplantar pustular psoriasis and nail psoriasis, but succuss rates are much lower in these atypical patterns of disease.
  • Patient monitoring:
  • --regular blood count
    --renal and liver function tests
    --eye examination
  • Combined therapy:
  • --etretinate or acitretin
    --dithranol
    --topical corticosteroids
    --cytotoxic drug
  • Adverse effects of PUVA:
  • --Erythema and frank sunburn are the commonest effects.
    --itching
    --cataract
    --Immune function abnormaly (reduce T-cell and its function, inhibition of lymphocyte DNA synthesis, delayed hypersensitivity responses)
    --nausea
    --pruritis
    --mild facial dermatitis
    --pigmentation
    --photo-onycholysis
    --bullae of generalized pemphigoid
    --hypertrichosis in females
    --lichenoid eruptions
    --actinic keratosis
    --superficial actinic porokeratosis
    --LE-like syndrome
  • The carcinogenic hazard of PUVA:
  • --It is undisputed that solar UV radiation is a major etiological factor in SCC, BCC and malignant melanoma in humans. Psoralens are known to be mutagenic and DNA damage has been induced by PUVA.
    --PUVA may induce AML and a preleukemic state.
  • PUVA using other psoralens:

  • --5-MOP
    --Trimethylpsoralen
    --3-carbethoxypsoralen
  • PUVA therapy with topically applied psoralens:

  • --8-MOP
    --Trimethylpsoralen
    --Advantage: avoidance of nausea
    --Disadvantage: risk of severe local phototoxic reactions with blistering, and the production of unsightly, patchy pigmentation.
  • Cyclosporin (Cyclosporin A, CyA):
    • Its inhibitory effects on T-cells, a possibility which has substantially affected attitudes towards pathogenic mechanism in psoriasis.
    • It is active orally and it should be given only to patients with sufficiently severe disease.
    • Contra-indication:
  • --renal dysfunction
    --uncontrolled hypertension
    --past or present malignancy
    --history of epilepsy
    --acute infection
    --pregnancy
    --lactation
    --immunosuppressive therapy
    --concomitant therapy with nephrotoxins
    --previous serious side-effect from CyA and known ----hypersensitivity
  • Relative contra-indication:
  • --abnormal liver function
    --malabsorption
    --drug or alcohol abuse
  • Withdrawal =>severe psoriasis relapse within weeks
  • Side-effect:
  • --dose-related hypertension
    --nephrotoxicity
    --increase the risk of malignancy
  • Miscellaneous oral and topical agents:
    • Vitamin D3 (effctive: orally=topical)
  • --inducing keratinocates differentiation and inhibition of T-cell proliferation.
  • 5-Lipoxygenase inhibitors
  • Fish oil
  • --interference with arachidonic acid metabolism.
  • Zidovudine (azidothymidine)
  • Systemic therapy for severe psoriasis: conclusions

  • Pustular forms of psoriasis:
    1. Definition:
    Neutrophilic accumulation in the epidermis is characteristic of all types and patterns of psoriasis and histologically all psoriasis is "pustular".
    2. A convenient classification is as follows:
  • Localized pustular psoriasis:
    • chronic palmoplantar
    • acute palmoplantar (pustular bacterid)
    • acrodermatitis continua
  • Generalized pustular psoriasis:
    • acute
    • of pregnancy
    • infantile and juvenile
    • circinate
    • localized (not hands and feet)

  • Localized pustular psoriasis:
    1. Chronic palmoplantar pustular psoriasis (PPP)
    A common condition in which erythematous and scaly plaques studded with sterile pustules persist on the palms or soles. The disease is chronic and very resistant to treatment.
  • Pathogenesis:
  • Maybe association with psoriasis vulgaris or has family history of it.
  • HLA-B13 (-)
  • HLA-B17 (-)
  • Provocative factors:
    • Lithium
    • Tonsils is a site of relevant focal infection.
  • Clinical features:
    • Adults, starts in the fifth or sixth decade or earlier
    • A modest preponderance of women.
    • one or more well-defined plaques
    • Hands: thenar eminence > hypothenar eminence or central palm or distal palm
    • Feet: instep, the medial or lateral border of the foot at the level of the instep or the sides or back of the heel
    • Symmetrical on the hands or feet is common
    • Dusty red and often scaly
    • Pustules are present, the desiccated pustule is exfoliated.
  • Differential diagnosis:
    • Tinea
    • Secondary infection of eczema
    • Chronic allergic contact dermatitis
    • Chronic acropustulosis
  • Prognosis:
    • The usual course is prolonged.
    • Temporary spontaneous remission
    2. Acute palmoplantar pustular psoriasis:
  • Rare, acute, monomorphic eruption of sterile pustules occurring on all aspects of the hands and feet.
  • Distribution:
  • palms, soles, and palmoplantar aspects of digits or dorsa of the hands and feet.
  • The term "bacterid" implies that the eruption is provoked by a remote bacterial infection.
  • D/D: acute leucocytoclastic vasculitis with immune complex deposition.
  • 3. Acrodermatitis continua
  • Definition:
  • A chronic sterile pustular eruption affecting initially the tips of fingers or toes which tends slowly to extend locally but which, in adults, may evolve into generalized pustular psoriasis.
  • Clinical features:
    • Children, female is common
    • starts on finger or thumb more often than on a toe
    • Koebner phenomena or infection induced
    • bordered by a fringe of undermined epidermis, irregular, often sodden and preceded by a line of vesiculopustules.
    • slow proximal extension
    • The nail plate may be completely destroyed.
    • osteolysis of the tuft of the distal phalanx
    • digits' end may become wasted and tapered, like scleroderma.
    • Cold weather may be exacerbation
    • evolve into generalized pustular psoriasis, especially in the elderly.
  • Differential diagnosis:
    • staphyloderma
    • pulp infection
    • herpetic whitlow
    • tinea
    • contact dermatitis
    • candidiasis
    • parakeratosis
  • Histopathology:
    • Intra-epidermal pustule packed with neutrophils.
  • Management:
    • Topical therapy:
  • --tar-impregnated occlusive bandages
    --topical corticosteroid
    --PUVA
  • Oral therapy:

  • --tetracycline
    --clomocycline
    --colchicine
    --clofazimine
    --sulphapyridine
    --dapsone
    --MTX
    --hydroxyurea
    --oral corticosteroid
    --etretinate
    --CyA
  • Radiotherapy

  • Generalized pustular psoriasis:
    Generalized pustular psoriasis (GPP) is an uncommon variant of psoriasis vulgaris in which an acute, subacute or occasionally chronic eruption has sterile pustulosis as its central feature.
  • Relationship to psoriasis vulgaris:
  • Patients may have phases of ordinary psoriasis before or after the GPP.
  • Provocation factors:
    • Von Zumbusch's (acute) original patient was provoked by irritating topical therapy.
    • coal tar and dithranol
    • infection
    • pregnancy
    • hypocalcemia
    • drug: especially corticosteroid
    • Withdraw of systemic steroid
  • HLA-B27(+)
  • Histopathology:
    • The inflammation is more intense in acute GPP than the other types.
    • lymphocytes infiltration
    • vessels edema
    • spongioform pustule formation (Kogoj)
    • acanthosis with elongation of rete ridges.
    • parakeratosis

    1. Acute generalized pustular psoriasis (von Zumbusch):

  • Clinical features:
    • Typical type: early onset, develops into pustular psoriasis after some years, after provocation by steroid withdrawal.
    • Atypical type: later onset, acral or flexural in distribution. A rapid and apparently spontaneous progression to the generalized pustular form follows.
    • Burning erythema that spreads in hours to result in large areas of fiery-red skin.
    • pin-point pustules =>clusters
    • lakes of pus, isolated pustules, circinate lesions, plaques of erythema with pustular collarettes or a generalized erythroderma.
    • fever, generalized weakness, severe malaise, leukocytosis
    • Nails: thickened or separated by subungual lakes of pus.
    • buccal mucosa and tongue may be involved.
    • Remission occurs within days or weeks, but relapses are common.
  • Complications:
    • hypoalbuminemia =>hypocalcemia
    • oligemia
    • liver damage or even jaundice
    • deep vein thrombosis =>fatal pulmonary embolism
    • staphylococcal infection
    • inflammatory polyarthritis
    • gross hair loss
    • telogen effluvium
  • Laboratory findings:
    • absolute lymphopenia
    • PMN reduce
    • plasma albumin, zinc and calcium may low
    • ESR is usually raised.
    • hyperlactatemia (secondary to hyperproliferation).

    2. Generalized pustular psoriasis of pregnancy:

  • Definition:
  • A rare eruption, occurring especially in pregnancy with the features of generalized pustular psoriasis but with a tendency to be symmetrical and grouped and often starting in the flexures.
  • Pathogenesis:

    • before MC
    • progesterone or clomiphene will produce pustular exacerbation.
    • Impetigo herpetiformis with hypocalcemia is an entity separate from GPP occurring in pregnancy.
  • Clinical features:
    • last trimester but may be earlier in the first month of pregnancy
    • Risk of placental insufficiency leading to stillbirth, neonatal death of the child or fetal abnormalities.
  • Prognosis:
    • may recur
  • Laboratory findings:
    • hypocalcemia
    • lowered levels of vitamin D
  • Treatment:
    • mestranol/ethynodiol combinition orally

    3. Infantile and juvenile pustular psoriasis:

  • male preponderance
  • Systemic symptoms are often absent and spontaneous remissions occur.
  • 2~10 years at onset
  • Zumbusch pattern but annular and circinate forms are seen.
  • The prognosis is variable but the disease may terminate spontaneously or develop into more tractable psoriasis vulgaris.
     
    4. Circinate and annular pustular psoriasis:
  • more characteristic of the subacute or chronic forms of widespread pustular psoriasis.
  • discrete areas of erythema which become raised and edematous.
  • slow centrifugal spread may mimic erythema annulare centrifugum.
  • pustules appear peripherally on the crest of the advancing edge.
  • 5. Localized forms of generalized pustular psoriasis:
  • D/D:
    • palmoplantar pustulosis
    • acropustulosis
    • napkin psoriasis
    • psoriasis vulgaris following prolonged irritant topical therapy.
    • subcorneal pustular dermatosis
    • pustular lesions in Reiter's disease
    • acute pemphigus foliaceus
    • migratory necrolytic eruption of glucagonoma
    • bowel by-pass syndrome
    • Sweet's syndrome
    • Behcet's syndrome
    • staphyloderma
    • rampant impetigo
    • candidiasis
    • pustular drug druption
  • Management of generalized pustular psoriasis
    • Admission to hospital
    • Withdrawal of provocative factors
    • General measures:
  • --conservative treatments such as bedrest, sedation, bland local application, fluid and protein replacement, adequate ambient temperature.
  • Topical therapy:
  • --completely bland creams or lotions
    --weak corticosteroid cream
    --contra-indication: tar and dithranol
  • Systemic therapy:
  • --MTX
    --razoxand
    --dapsone or sulphapyridine
    --corticosteroid (oral, parenteral, topical)
    --etretinate alone or combine with PUVA
    --PUVA
    --cyclosporin
  • Prognosis:
    • Von Zumbusch psoriasis: prognosis good
    • GPP developing from acropustulosis: the worst prognosis
    • GPP of childhood: prognosis good GPP which onset late: poor prognosis, death is due to cardiac failure or resperatory infection.
    • Patients with preceding ordinary psoriasis had a better prognosis than those with atypical prepustular psoriasis.

  • Arthropathic psoriasis (Psoriatic arthritis):
    1. 0.02~0.1%in population, 2~25%of psoriatics
    2. Definition:
    The association of psoriasis of the skin and/or nails with a peripheral and/or spinal arthropathy, and usually a negative serological test for rheumatoid factor.
    3. Etiology and pathogenesis:
  • genetic
  • usually association with HLA-B27
  • enviromental factors
  • 4. 40~60 years is the peak age
    5. Clinical patterns:
  • asymmetrical DIP joints
  • arthritis mutilans with osteolysis of phalanges and metacarpals
  • symmetrical polyarthritis (RA-like)
  • oligoarthritis with tenosynovitis of hands
  • D/D: ankylosing spondylitis, psoriasis arthritis may with peripheral arthritis
  • nail dystrophy

  • References:
    1. ROOK WILKINSON EBLING TEXTBOOK OF DERMATOLOGY by R.H. CHAMPION J. L.BURTON K. J.G. EBLING
    2. COLOR ATLAS AND SYNOPSIS OF CLINICAL DERMATOLOGY by THOMAS B. FITZPATRICK RICHARD ALLEN JOHNSON KLAUS WOLFF MACHIEL K. POLANO DICK SUURMOND

    Suggestion to this case


    Editor: 林育佳,蔡文仁,黃建元,李文瑞
    Text: 蔡宏彬
    Supervisor: Yu-Chuan Li, M.D., Ph.D.