National survey of psoriasis flares after 2009 monovalent H1N1/seasonal vaccines.

BACKGROUND: Psoriasis is a common chronic immune-mediated disease resulting from interactions of a genetic background with environmental triggering factors such as stress and infection. So far, there is very limited information available about the impact of vaccine stimuli on psoriasis course.

OBJECTIVE: To collect cases of psoriasis flares occurring after vaccination through a national survey.

METHODS: We investigated cases of onset or flare of psoriasis occurring within 3 months following the 2009 monovalent H1N1/seasonal vaccination during the campaign of the 2009-2010 flu seasons in France.

RESULTS: Ten patients, 6 men and 4 women with a median age of 44 years (range 9-88), were reported with a psoriasis of new onset (n = 7) or with a worsening of previously diagnosed psoriasis (n = 3) within a median time period of 8 days following vaccination. Nine of them presented with a mixed guttate/plaque clinical phenotype, and 1 showed 2 successive generalized pustular psoriasis (GPP) flares after 2 different vaccine injections.

CONCLUSION: The short time interval between vaccination and onset of psoriasis flares, the lack of other triggers and the flaring sequence following 2 different vaccines in a GPP patient suggest a possible association between the 2009 monovalent H1N1/seasonal vaccination and psoriasis flaring in the collected cases. Nevertheless, the likely very low incidence of psoriasis following vaccination emphasizes the safe profile and the relevance of vaccination strategies in psoriasis patients, especially in candidates for immunosuppressive treatments.