What is Psoriasis ?
It is a common, chronic and non-inflammatory skin disease characterized by well-defined, slightly raised, dry erythematous macules with silvery scales and typical extensor distribution. 1-3 % of the population suffers from psoriasis.
The course of disease is unpredictable but is usually chronic with exacerbation and remissions.It is Seen between 15 and 40 years and Rare under 10 years. It is a heredo- familial disease brought on by stress, anxiety, mental trauma, fever, physical injury, digestive upsets, etc. on a genetic constitution.
- Susceptible gene at the distal end of chromosome 17q.
- Marker appear to be independent of HLA CW 6.
- Those antigen are linked with CW6 with which psoriasis is strongly associated.
- One parent psoriatic then there is 15% chances to their child.
- Both parent psoriatic then there is 50% chance to offspring.
- Non psoriatic parents there is 10% chances.
- Increased levels of prostaglandins. Leukotrines and hydroxyeicosatetraenoic acids in the epidermis.
- Decreased cAMP and increased cGMP are found in lesions and beta-adrenoceptor antagonistic drugs may exacerbate psoriasis by inhibiting cAMP formation.
- Polyamines are elevated in lesional skin, due to increased activity of ornithine decarboxylase and may be intimately associated with cellular proliferation
- The calcium-calmodulin complex may regulate epidermal cell-proliferation by influencing phospholipase A2 and cAMP phosphodiesterase activity.
- Activation complement system
- Attraction of neutrophils to the area.
- Elevation of certain interleukins (IL-1, IL-2, IL-6 and IL-8) and growth factors (TNF a, TGF a)
- Adhesion molecules are expressed or up regulated in lesions of psoriasis.
- The dermal mononuclear infiltrate is mainly of T - lymphocytes, most of which are helper type.
- The increased epidermal cell proliferation of psoriasis is related to the increased replication and metabolism of dermal fibroblasts.
- Precipitating factors :
- Presence of diabetes
- Purine in diets
- Result from a complement – mediated reaction localized to the stratum corneum.
- Exogenous or endogenous damage to the stratum corneum antigens
- Formation of specific auto antibodies
- Antibodies bind to the stratum corneum
- Fix complement system and activate the complement cascade.
- Neutrophil recruitment and activation
- Release proliferation factors for the underlying keratinocytes, resulting in increased epidermal turnover.
Clinical features :
- The typical distribution is extensor.
- Psoriasis exhibits itself as dry, well defined macules, papules and plaques of erythema with layer-upon-layer of silvery scales.
- The typical lesions are coin shaped, by confluence, big plaques of the size of the palm of a hand
- Slightly raised above the surface of the skin
- Koebner’s phenomenon
- The scalp is involved in almost all cases .
- Nails show three types of lesions:
- Separation of the distal portion of the nail form the nail bed and walls.
- Thickening of the nail, accompanied by the collection of hyperkeratotic debris under the nail.
- Corona Psoriatica
- The palms of the hands are involved more commonly .
- Lesions consist of well defined patches of hyperkeratosis and fissures, on eythematous bases
- Lesions are bilaterally symmetrical.
- Psoriasis Inversus
Candle-Grease sign (Tache de bouge).
plaque guattate psoriasis
psoriasis on the feet
- Guttate psoriasis (Plaque Psoriasis, Psoriasis Vulgaris)
- Psoriasis arthropathica
- Inverse psoriasis
- Pustular Psoriasis
- Erythrodermic psoriasis
- Erythrodermic psoriasis
- Flexural psoriasis
- The family history of psoriasis.
- The typical distribution of the lesions on the scalp, elbows, knees, the front of the legs, back and nails.
- Well-defined, non-indurated, dry, erythematous areas with silvery layer-upon-layer scaling.
- The candle-grease sign, Koebner’s phenomenon and pin-point bleeding upon removal of the scale.
- Little or no itching.
- History of previous attacks and seasonal variations of disease.
- Typical histopathology.
- Laboratory findings:
- The erythrocyte sedimentation rate is usually increased in erythrodermic and generalized pustular psoriasis and there is leucocytosis in the latter.
- In the erythrodermic psoriasis there is loss of protein and iron resulting hypoproteinaemia and mild anemia.
- Serum and red cell folate and serum B12 tend to be low.
- Blood hydroxyproline is sometimes raised and also there is negative nitrogen balance.
- Uric acid level may be elevated in psoriasis, causing confusion with gout in psoriatic arthritis.
- Radiographs of affected joints can be helpful in differentiating types of arthritis.
- Immunoglobulin is generally normal but selective IgA deficiency and monoclonal IgG gammaglobinopathy are documented in association with psoriasis.
- Pityriasis rosea
- Seborrhoeic Dermatitis
Disease is non-infectious.
General health and longevity are unaffected though the majority of patients suffer from the disease on and off throughout their lives.
The course is chronic with varying periods of intermission.
Flexural, erythrodermic and pustular psoriasis take longer to heal than the typical variety. The palmar and nail lesions are rather resistant to treatment.
Self care :
- Use moisturizer.
- Maintain a healthy weight.
- Avoid sun exposure.
- Follow a nutritious diet.
- Take daily baths.
Diagnostic Criteria :
- Diagnosis of psoriasis is completely dependent upon the clinical findings.
- Typical distribution of lesion on scalp, elbow, knees, back and nails with well defined , non indurated dry silvery colored with layer upon scaling.
- Little or no itching.
- Auspitz sign, Candle-grease sign, Koebner’s phenomenon may be present.
- If after examination the skin, nails & scalp, the diagnosis is in doubt, then skin biopsy may helpful for final confirmation.
- Family history of psoriasis.
- History of previous attack.
- Patients having other skin eruption, diabetes, tuberculosis, leprosy, seborrhoeic dermatitis, pityriasis rosea are not taken into consideration.
- After clear onset of the patient he / she will be selected for the clinical trial.
- Sample Size :
- In view of the design of this study. The sample size was set at 60 cases applying
- formula n=[(z1-a-zb)]
- Study of Instruments
- Following laboratory tests were done.
- Sikn biopsy ( In needed cases)