Exacerbation of Psoriasis under Efalizumab Therapy

Background: Efalizumab is a recombinant humanized IgG1-κ isotype monoclonal antibody that binds to CD11a, inhibiting T-cell activation. It has been approved for the treatment of moderate to severe plaque psoriasis. Efalizumab has been associated with the development of skin eruptions during the administration period, and this probably represents the potential psoriasis events observed during its administration. Objective: We report a case of exacerbation of psoriasis under efalizumab administration. A reversible increase in lymphocyte count with normal total white blood cell count was also noticed. Conclusion: Larger series are probably needed to establish clinical and histopathologic criteria and to determine the terminology used regarding the psoriasis adverse events seen with efalizumab treatment. Anteeedents: L'efalizumab est un anticorps monoclonal humanise recombinant de type IgG1 kappa qui se lie a la sous-unite CD11a inhibant ainsi l'activation des lymphocytes T. L'utilisation de l'efalizumab a ete approuvee dans le traitement des plaques de psoriasis modere a grave. Des eruptions cutanees, associees a des poussees de psoriasis, peuvent survenir durant le traitement. Objectif: Nous rapportons un cas d'exacerbation du psoriasis durant un traitement a l'efalizumab. On a egalement note une augmentation reversible des lymphocytes avec un niveau normal de leucocytes. Conclusion: Des cas additionnels sont probablement necessaires pour etablir les criteres cliniques et histopathologiques et determiner la terminologie utilisee pour decrire les evenements de psoriasis indesirables durant un traitement a l'efalizumab.