Do any factors precipitate generalized pustular psoriasis?

The most important inciting factor is the administration of systemic corticosteroids. In a study of 104 patients, corticosteroids were implicated as the precipitating factor in 37 patients (36%). This association is one of the primary reasons that psoriasis is not treated with systemic corticosteroids. Less common precipitating factors included infection (13%), hypocalcemia (9%), pregnancy (3%), and other drugs (e.g., terbinafine).

Baker H, Ryan TJ: Generalized pustular psoriasis: a clinical and epidemiologic study of 104 cases, Br J Dermatol 80:771–793, 1968.