F The  word – ‘Psor’ means Itching and ‘iasis’ means  condition

F One of the oldest recorded skin diseases – a challenge for the physicians  till today

 Non- contagious life long skin diseases

 About 1.5 to 2% of total world’s population


Psoriasis may be defined as a chronic

 inflammatory disease  of skin with relapse  &

 remission characterized by well marked

 erythematous  papules  & plaques  which is

usually covered by dry silvery scales.

Main types of Psoriasis:

(1) Plaque Psoriasis-80% most common

(2) Guttate psoriasis

(3)Pustular psoriasis

(4) Inverse psoriasis

(5) Erythrodermic psoriasis

Incidence : About 1.5% – 2% of total population

Age : The onset of psoriasis constitute a life     long threat !

 Peak onset : young adult ( 20 -30 yrs)

Sex : Male : Female = Equal

Race : All

Aetiology : Exact cause Unknown

But factors may flare up psoriasis :

Genetic :   1/3 family history may present

                      HLA Cw6, HLA-B13, HLA-B17

Season : Winter

Sunlight : Strong sun light exposure is found to be initiated    psoriasis


Infection : Streptococci, HIV, HCV, HBV, Chlamydia

Pregnancy : Improve but deteriorate post partum period

Metabolic : Hypocalcaemia

Drugs : HPA-FLIM

Anti-Hypertensive :Beta blockers, ACE inhibitors, Calcium channel blockers(Nifidipine,)

Anti-Psychotic : Lithium

Antibiotic : Sulphonamides

Anti-Fungal : Terbinafine

Anti-Lipid : Gemfibrozil

Anti-Inflammatory : NSAIDs, With drawl systemic Steroids.

Anti-Malarial : Chloroquine

Pathogenesis :

 There is accelerated epidermopoiesis

T- cell Based immunopathogenesis

Mainly Cytokines responsible for Psoriasis

TNF alpha, IFN gamma, IL-1

The lesion of psoriasis result from an increase in epidermal cell turnover. The cell’s transit time from the basal layer of the epidermis to the stratum corneum is decreased from the normal 28 days to 3 or 4 days.

Course and Prognosis

The prognosis for control is good

‘ Psoriasis  may undergo  a remission for several months to years.

‘ The habit of scratching and rubbing  the must be  avoided to maintain the remission

Clinical features :

Erythematous hyperkeratotic mild to moderate pruritic  papules and plaques almost bilaterally symmetrical on extensor distribution

Cardinal features ;

Sharply demarcated with clear cut border

Surface consists of non-coherent silvery scales

Under the scales the skin has glossy ,homogenous erythema

Auspitz’s sign positive :Pin pointed bleeding where a psoriatic scale forcibly removed (Severely thinning of epidermis over the tip of dermal papilla)

Others : Koebner’s phenomenon

:Isomorphic response resulting development of same type of new  lesion at the site of injury or trauma

Nail changes : Nail pitting (deeper & broader), Oil spot ( rounded area of onycholysis), Sub-ungual hyperkeratosis, up lifting of distal portion of nail plate

Psoriatic arthopathy or arthritis

Severity of Psoriasis

According to Body Surface Area (BSA):

Mild < 10% BSA

Moderate > 10% BSA

Severe > 30% BSA

According to Psoriasis Area Severity Index (PASI)

Mild < 10% PASI

Moderate > 10-20% PASI

Severe > 20% PASI

Complications  of Psoriasis :

Erythroderma or Exfoliative dermatitis

Psoriatic arthopathy

Pustular psoriasis

Secondary bacterial infections

Hypocalcaemia, Hypoprotenaemia,Hyperuricaemia

Investigation :

For the diagnosis of disease :

Skin biopsy for histopathological examination

Munro microabscesses present at stratum corneum

thinning or absence of granular layer

Regular elongation of rete ridges

Elongation & edematous dermal papilla with tortuous blood vessels

To exclude the D/D :

Pityriasis rubra pilaris


Lichen planus

Pityriasis rosea

Secondary Syphilis

Seborrhoeic Dermatitis

Tinea capitis

Investigations to find out associated diseases / conditions


 Chlamydial infections

 HCV infection

 HBV infection

 HIV infection

 Streptococcal infection

Investigations for therapeutic purposes

Example : Before MTX  therapy need to investigate the follows

CXR P/A view


Serum Creatinine


Laboratory abnormalities in Psoriasis

Serum Uric Acid é

 Serum Calciumê

 ESR é

 Hb % ê

 C – reactive protein é

 ASO é (if streptococcal infection associated)

Skin biopsy for histopathological examination.

Management of  Psoriasis

There is no magic cure for psoriasis , but many treatment options  can help to control it & its symptoms . Sometimes spontaneous remission may occur or it can remain on the body for longer period of time.

ÜTreatment selection is very important ÜEffectiveness vary from person to person

ÜTreatment should never be worse than psoriasis itself

ÜScalp treatment must be continued  or repeated until get adequate control of lesion. This can take up to  8 weeks  or longer

ÜModerate sunlight exposure   is often helpful. Avoid sunburn , since psoriasis may develop in areas of injured skin

Modalities of Treatment

General measures

◄Reassurance and explanation

◄Emotional support


Topical measures



Salicylic acid



Vit. D3 analogue(Calciprotriol)

Calcineurin inhibitor(Tacrolimus)


UV therapy


Narrowband UVB

Broadband UVB

Systemic measures





Mycofenolate mofetil



Supportive measures

  Anti-histamine for itching :

Tab.   Mebhyholin(50mg) 1 tab. 12 hourly

  Cap. Fish Oil ( Omega-3)

   Remove stress, anxiety,depression ; Tab. Amitryptyline(10mg) 1tab at night

   Vitamin B – complex supplementation daily

Treatment of Complications if any

Psoriatic arthritis : Bed rest, Analgesics, for 2-3 weeks

Secondary bacterial infections : Antibiotics : Azithromycin (500mg) once daily dose for 7-10 days


Psoriasis is a life long disease with relapse and remission.

Non-contagious  & Usually Non-infectious

Counseling is important— severe psychological trauma may lead to depression

One of the common skin diseases- about 1.5 – 2% of total world population

Mild to moderate sun exposure is beneficial but sunburn should be avoided.

Psoriasis tends to be remarkable symmetric. It usually spare the face.

Psoriasis is commonly a cause of nail deformity which is often mistaken for, and treated incorrectly as nail fungal infection (Onychomycosis)

Hair fall usually does not occur due to psoriasis.

Maximum cases of Psoriasis are non-pruritic.

Biologics are newer effective drugs for psoriasis but very expensive

Use of emollient, Keratolytic agent, Rational use of topical steroid are the simple effective way to control the disease.

Main 4 systemic drugs

   (MTX,Acetretin,Cyclosporin,Mycophenolate mofetil) can be used as rotational therapy for psoriasis patients in the context of Bangladesh.

Systemic steroids are contraindicated in Psoriasis.

Emergency condition of psoriasis is developed due to systemic steroid and Homeopathy

Arthritis may be presented at first in 10% of psoriasis patients with out skin lesion.

Allergic foods,scratching,Alcohol must be strictly avoided and DM should be controlled.

Viva: Name some skin diseases associated with arthritis?




Rheumatoid arthritis


Gonococcal arthritis


Erythema nodosum leprosum


Sweet syndrome

Reiter’s syndrome

Erythema nodosum