Psoriasis is a chronic autoimmune inflammatory skin disease that affects 1% to 3% of the global population. Because no psoriasis biomarkers are available to assess disease severity, clinical measures are used in daily practice and in research to measure both severity and treatment response. In the clinic, psoriasis may be graded by the dermatologist as mild to severe and improvement measured as worse, unchanged, better, much better, or clear. However, these scales are insufficient for clinical trials, where objective tools that are reliable, valid, and consistent from investigator to investigator are needed to quantify disease activity more precisely. The aim of this research is to update the reader on how to assess the major evaluation components of psoriasis severity and to review the most common global and local psoriasis scales used by the clinical trial physician (Psoriasis Area and Severity Index, Physician's Global Assessment, Target Lesion Psoriasis Severity Scale, Lattice System Physician's Global Assessment).
KaufmannR., BibbyA.J., BissonnetteR.A new calcipotriol/betamethasone dipropionate formulation (Daivobet) is an effective once-daily treatment for psoriasis vulgaris. Dermatology.2002; 205(4): 389–93.
2.
RappS.R., FeldmanS.R., ExumM.L., FleischerA.B.Jr., ReboussinD.M.Psoriasis causes as much disability as other major medical diseases. J Am Acad Dermatol.1999; 41(3 Pt 1): 401–7.
3.
FeldmanS.R., KruegerG.G.Psoriasis assessment tools in clinical trials. Ann Rheum Dis.2005; 64(suppl 2): ii, 65–8.
4.
BigbyM., GadenneA.S.Understanding and evaluating clinical trials. J Am Acad Dermatol.1996; 34(4): 555–590.
5.
JemecG.B., WulfH.C.The applicability of clinical scoring systems: SCORAD and PASI in psoriasis and atopic dermatitis. Acta Derm Venereol.1997; 77(5): 392–3.
6.
LangleyR.G., EllisC.N.Evaluating psoriasis with Psoriasis Area and Severity Index, Psoriasis Global Assessment, and Lattice System Physician's Global Assessment. J Am Acad Dermatol.2004; 51(4): 563–9.
7.
Berth-JonesJ., ThompsonJ., PappK.A study examining inter-rater and intrarater reliability of a novel instrument for assessment of psoriasis: the Copenhagen Psoriasis Severity Index. Br J Dermatol.2008; 159(2): 407–12.
8.
RamsayB., LawrenceC.M.Measurement of involved surface area in patients with psoriasis. Br J Dermatol.1991; 124: 565–70.
9.
SavolainenL., KontinenJ., RöningJ., OikarinenA.Application of machine vision to assess involved surface in patients with psoriasis. Br J Dermatol.1997; 137(3): 395–400.
10.
SavolainenL., KontinenJ., AlataloE., RöningJ., OikarinenA.Comparison of actual psoriasis surface area and the psoriasis area and severity index by the human eye and machine vision methods in following the treatment of psoriasis. Acta Derm Venereol.1998; 78(6): 466–7.
11.
OrmerodA.D., DwyerC.M., WellerR., CoxD.H., PriceR.A comparison of subjective and objective measures of reduction of psoriasis with the use of ultrasound, reflectance colorimetry, computerized video image analysis, and nitric oxide production. J Am Acad Dermatol.1997; 37(1): 51–7.
12.
KanthrajG.R., SrinivasC.R., ShenoiS.D., DeshmukhR.P., SureshB.Comparison of computer-aided design and rule of nines methods in the evaluation of the extent of body involvement in cutaneous lesions. Arch Dermatol.1997; 133(7): 922–3.
13.
FeldmanS.R., FleischerA.B.Jr., ReboussinD.M.The self-administered psoriasis area and severity index is valid and reliable. J Invest Dermatol.1996; 106(1): 183–6.
14.
FleischerA.B.Jr., FeldmanS.R., DekleC.L.The SAPASI is valid and responsive to psoriasis disease severity changes in a multi-center clinical trial. J Dermatol.1999; 26(4): 210–15.
15.
SampognaF., FleischerA.B.Jr., ReboussinR.M.Performance of the self-administered psoriasis area and severity index in evaluating clinical and sociodemographic subgroups of patients with psoriasis. Arch Dermatol.2003; 139(3): 353–8.
16.
SpulsP.I., LecluseL.L., PoulsenM.L., BoxJ.D., SternR.S., NijstenT.How good are clinical severity and outcome measures for psoriasis?: quantitative evaluation in a systematic review. J Invest Dermatol.2010; 130(4): 933–43.
17.
GottliebA.B., ChaudhariU., BakerD.G., PerateM., DooleyL.T.The National Psoriasis Foundation Psoriasis Score (NPF-PS) system versus the Psoriasis Area Severity Index (PASI) and Physician's Global Assessment (PGA): a comparison. J Drugs Dermatol.2003; 2(3): 260–6.
18.
FredrikssonT., PetterssonU.Severe psoriasis—oral therapy with a new retinoid. Dermatologica.1978; 157(4): 238–44.
19.
NaldiL., SvenssonA., DiepgenT.Randomized clinical trials for psoriasis 1977–2000: The EDEN survey. J Invest Dermatol.2003; 120(5): 738–41.
20.
AshcroftD.M., Wan PoA.L., WilliamsH.C., GriffithsC.E.Clinical measures of disease severity and outcome in psoriasis: a critical appraisal of their quality. Br J Dermatol.1999; 141(2): 185–91.
21.
FeldmanS.R.The design of clinical trials in psoriasis: lessons for clinical practice. J Am Acad Dermatol.2003; 49(2): S62–5.
22.
EllisC.N., KruegerG.G., Alefacept Clinical Study Group. Treatment of chronic plaque psoriasis by selective targeting of memory effector T lymphocytes. N Engl J Med.2001; 345(4): 248–55.
23.
BhushanM., BleikerT.O., BallsdonA.E.Anti-E-selectin is ineffective in the treatment of psoriasis: a randomized trial. Br J Dermatol.2002; 146(5): 824–31.
24.
CarlinC.S., FeldmanS.R., KruegerJ.G., MenterA., KruegerG.G.A 50% reduction in the Psoriasis Area and Severity Index (PASI 50) is a clinically significant endpoint in the assessment of psoriasis. J Am Acad Dermatol.2004; 50(6): 859–66.
25.
HarariM., ShaniJ., HristakievaE., StaninirovicA., SeidlW., BurdoA.Clinical evaluation of a more rapid and sensitive Psoriasis Assessment Severity Score (PASS), and its comparison with the classic method of Psoriasis Area and Severity Index (PASI), before and after climatotherapy at the Dead-Sea. Int J Dermatol.2000; 39(12): 913–8.
26.
MarksR.Measurement of the response to treatment in psoriasis. J Dermatol Treat.1996; 7(1)(suppl): S7–10.
27.
JacobsonC.C., KimballA.B.Rethinking the Psoriasis Area and Severity Index: the impact of area should be increased. Br J Dermatol.2004; 151(2): 381–7.
28.
BeutnerK., ChakrabartyA., LemkeS., YuK.An intra-individual randomized safety and efficacy comparison of clobetasol propionate 0.05% spray and its vehicle in the treatment of plaque psoriasis. J Drugs Dermatol.2006; 5(4): 357–60.
29.
WeinsteinG.D., KruegerG.G., LoweN.J.Tazarotene gel, a new retinoid, for topical therapy of psoriasis: vehicle-controlled study of safety, efficacy, and duration of therapeutic effect. J Am Acad Dermatol.1997; 37(1): 85–92.
