Pustular psoriasis.

Pustular psoriasis may appear as localized pustular psoriasis, which runs a chronic course, or, in a more severe state, generalized pustular psoriasis. Precipitating factors influencing both local and generalized forms include various drugs (eg, lithium, hydrochloroquine), irritative topical therapy (eg, coal tar), dental and upper respiratory infections, pregnancy, and solar irradiation. Both adults and children are affected, but infantile and juvenile pustular psoriasis is rare. It is recommended that provoking factors be eliminated as the first line of management. Short-contact anthralin therapy and topical psoralen/ultraviolet A can be used in treating localized pustular psoriasis. Methotrexate, hydroxyurea, etretinate, dapsone, cyclosporin A, as well as systemic corticosteroids may be needed in life-threatening cases.