Table 1

Definitions of commonly-used terminology used by the US National Psoriasis Foundation (NPF), the European Medicines Agency (EMEA) and this study.

Term

NPF [20]

EMEA [21]

This study


During treatment

Flare

Typical or unusual worsening of disease during treatment and/or the occurrence of new psoriasis morphologies.

Not defined.

Not used

Following treatment discontinuation

Recurrence

Not defined

The EMEA recommend the use of recurrence as an endpoint in long-terms studies provided that it is clearly defined.

The term 'inflammatory recurrence' includes (a) patients with worsening of psoriasis within 2 months of discontinuation from efalizumab treatment to a level less severe than a rebound and (2) patients who have discontinued a psoriasis treatment due to an inflammatory disease flare but, following discontinuation, require treatment to prevent a rebound.

Relapse

Loss of 50% of PASI improvement from baseline in patients who achieve a clinically meaningful response (≥ 50% improvement in PASI score from baseline).

A reduction of >50% in PASI from the achieved maximal improvement in PASI score.

Subjective alternative: a relapse of psoriasis necessitating the re-initiation of treatment.

A simple worsening of psoriasis beyond 2 months of therapy may represent the natural course of the disease (relapse) rather than a rebound associated with drug.

Not used

Rebound

A PASI of 125% of baseline or new generalized pustular, erythrodermic, or more inflammatory psoriasis occurring within 3 months of stopping therapy.

Worsening occurring after 3 months of therapy may represent the natural course of the disease rather than a rebound associated with the drug.

Worsening of psoriasis over baseline value (e.g. PASI>125%) or new pustular, erythrodermic or more inflammatory psoriasis occurring within 2 months of stopping therapy.

A 2-month boundary separating relapse and rebound is drawn on theoretical grounds and is more or less arbitrary.

Not used


PASI, Psoriasis Area and Severity Index

Papp et al. BMC Dermatology 2006 6:9   doi:10.1186/1471-5945-6-9

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