PASI | |
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Purpose | measurement of severity of psoriasis |
Psoriasis Area and Severity Index (PASI) is the most widely used tool for the measurement of severity of psoriasis. PASI combines the assessment of the severity of lesions and the area affected into a single score in the range 0 (no disease) to 72 (maximal disease). [1]
The body is divided into four sections (head (H) (10% of a person's skin); arms (A) (20%); trunk (T) (30%); legs (L) (40%)). Each of these areas is scored by itself, and then the four scores are combined into the final PASI. For each section, the percent of area of skin involved, is estimated and then transformed into a grade from 0 to 6:
Within each area, the severity is estimated by three clinical signs: erythema (redness), induration (thickness) and desquamation (scaling). Severity parameters are measured on a scale of 0 to 4, from none to maximum.
The sum of all three severity parameters is then calculated for each section of skin, multiplied by the area score for that area and multiplied by weight of respective section (0.1 for head, 0.2 for arms, 0.3 for body and 0.4 for legs).
PASI is widely used in clinical trials of therapies to treat psoriasis. Although absolute PASI score is often used to define entry into a trial, it is response to treatment that is important to measure efficacy and outcomes. This is usually presented as a percentage response rate; e.g., PASI 50, PASI 75, PASI 90, PASI 100.
PASI 75, for example, represents the percentage (or number) of patients who have achieved a 75% or more reduction in their PASI score from baseline. PASI 100 indicates patients who have achieved a complete resolution of all disease. By definition a patient who has achieved PASI 75 has also achieved PASI 50. There is a gradual tendency, as therapies become more effective to report higher efficacy rates in clinical trials - but aiming high may not be without risk of over-treating some patients. [2]
Psoriatic area assessment and severity assessments were found to be non-reproducible. Several automated procedure for more reproducible measurement of psoriatic area were developed, but were not suitable for large-scale trials. A method where the advantage of accurate computerized measurement of the area on the digital photograph was combined with physician's proficiency in determination of the edge of psoriatic lesion was published. [3] The patients were examined and photographed before and after the therapy with calcipotriol ointment or placebo. The psoriatic area was manually outlined on the patient's photographs by physician and the area was automatically measured by a computer. For comparison, the physicians also made standard psoriatic area assessment. Computer-aided measurement of psoriatic lesion area was found to improve the power of the clinical trial, compared to the standard approach. The physician's estimations of the psoriatic lesion area tend to overestimate. The adapted PASI index, where the psoriatic area was not converted into an area grade, but was maintained as a continuous variable, also improved the power of the clinical trial. The modified PASI which involves computer-aided area measurement as a continuous variable is named Computer aided psoriasis continuous area and severity score cPcASI.
PASI can be too unwieldy to use outside of trials, which has led to attempts to simplify the index (SPASI) for clinical use. [4]
While higher PASI scores indicate more severe psoriasis, it is difficult for patients or doctors to describe the clinical severity for any specific PASI number. Attempts have been made to address this problem by providing descriptions of psoriasis severity in evaluation systems, including the Psoriasis Global Assessment (PGA) and the Lattice-System Physician's Global Assessment (LS-PGA); a study compared and validated PASI, PGA, and LS-PGA. [5]
Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, or purple on some people with darker skin, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete body coverage. Injury to the skin can trigger psoriatic skin changes at that spot, which is known as the Koebner phenomenon.
Hidradenitis suppurativa (HS), sometimes known as acne inversa or Verneuil's disease, is a long-term dermatological condition characterized by the occurrence of inflamed and swollen lumps. These are typically painful and break open, releasing fluid or pus. The areas most commonly affected are the underarms, under the breasts, and the groin. Scar tissue remains after healing. HS may significantly limit many everyday activities, for instance, walking, hugging, moving, and sitting down. Sitting disability may occur in patients with lesions in sacral, gluteal, perineal, femoral, groin or genital regions; and prolonged periods of sitting down itself can also worsen the condition of the skin of these patients.
Psoriatic arthritis is a long-term inflammatory arthritis that occurs in people affected by the autoimmune disease psoriasis. The classic feature of psoriatic arthritis is swelling of entire fingers and toes with a sausage-like appearance. This often happens in association with changes to the nails such as small depressions in the nail (pitting), thickening of the nails, and detachment of the nail from the nailbed. Skin changes consistent with psoriasis frequently occur before the onset of psoriatic arthritis but psoriatic arthritis can precede the rash in 15% of affected individuals. It is classified as a type of seronegative spondyloarthropathy.
Alefacept is a genetically engineered immunosuppressive drug. It was sold under the brand name Amevive in Canada, the United States, Israel, Switzerland and Australia. In 2011, the manufacturers made a decision to cease promotion, manufacturing, distribution and sales of Amevive during a supply disruption. According to Astellas Pharma US, Inc., the decision to cease Amevive sales was neither the result of any specific safety concern nor the result of any FDA-mandated or voluntary product recall. On the other hand, usage of Amevive was associated with a certain risk of development systemic diseases such as malignancies. This drug was never approved for the European drug market.
The National Psoriasis Foundation (NPF) is the world's largest nonprofit organization serving people with psoriasis and psoriatic arthritis. The NPF provides information and services to help people manage their condition while supporting research to find a cure. In addition to serving more than 3 million people annually through patient and professional health education and advocacy initiatives, the NPF has funded more than $10 million in psoriatic disease research grants and fellowships.
Heinrich Koebner ; was a German-Jewish dermatologist born in Breslau.
In medicine, a finger tip unit (FTU) is defined as the amount of ointment, cream or other semi-solid dosage form expressed from a tube with a 5 mm diameter nozzle, applied from the distal skin-crease to the tip of the index finger of an adult. The "distal skin-crease" is the skin crease over the joint nearest the end of the finger. One FTU is enough to treat an area of skin twice the size of the flat of an adult's hand with the fingers together, i.e. a "handprint". Two FTUs are approximately equivalent to 1 g of topical steroid.
Psoriatic onychodystrophy or psoriatic nails is a nail disease. It is common in those with psoriasis, with reported incidences varying from 10% to 78%. Elderly patients and those with psoriatic arthritis are more likely to have psoriatic nails.
Psoriatic erythroderma represents a form of psoriasis that affects all body sites, including the face, hands, feet, nails, trunk, and extremities. This specific form of psoriasis affects 3 percent of persons diagnosed with psoriasis. First-line treatments for psoriatic erythroderma include immunosuppressive medications such as methotrexate, acitretin, or ciclosporin.
Generalized pustular psoriasis (GPP) is an extremely rare type of psoriasis that can present in a variety of forms. Unlike the most general and common forms of psoriasis, GPP usually covers the entire body and with pus-filled blisters rather than plaques. GPP can present at any age, but is rarer in young children. It can appear with or without previous psoriasis conditions or history, and can reoccur in periodic episodes.
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Stasis papillomatosis is a disease characterized by chronic congestion of the extremities, with blood circulation interrupted in a specific area of the body. A consequence of this congestion and inflammation is long-term lymphatic obstruction. It is also typically characterized by the appearance of numerous papules. Injuries can range from small to large plates composed of brown or pink, smooth or hyperkeratotic papules. The most typical areas where injuries occur are the back of the feet, the toes, the legs, and the area around a venous ulcer formed in the extremities, although the latter is the rarest of all. These injuries include pachydermia, lymphedema, lymphomastic verrucosis and elephantosis verrucosa. The disease can be either localized or generalized; the localized form makes up 78% of cases. Treatment includes surgical and pharmaceutical intervention; indications for partial removal include advanced fibrotic lymphedema and elephantiasis. Despite the existence of these treatments, chronic venous edema, which is a derivation of stasis papillomatosis, is only partially reversible. The skin is also affected and its partial removal may mean that the skin and the subcutaneous tissue are excised. A side effect of the procedure is the destruction of existing cutaneous lymphatic vessels. It also risks papillomatosis, skin necrosis and edema exacerbation.
The Psoriasis Index of Quality of Life (PSORIQoL) is a patient-reported outcome measure which determines the quality of life of patients with psoriasis. It is based on a needs-based approach to quality of life.
Ponesimod, sold under the brand name Ponvory, is a medication for the treatment of multiple sclerosis (MS).
The Eczema Area and Severity Index (EASI) is a tool for the measurement of severity of atopic dermatitis. It ranges from 0 to 72.
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The Dermatology life Quality Index (DLQI) is a ten-question questionnaire used to measure the impact of skin disease on the quality of life of an affected person. It is designed for people aged 16 years and above.
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