Palmoplantar pustulosis (PPP) is a chronic inflammatory disorder characterized by sterile pustules predominantly involving the palms and soles. PPP is refractory to various
therapies such as topical
ointment,
oral medicine, and
phototherapies. Pustulotic arthro-
osteitis (PAO) is a major comorbidity of PPP that severely impairs patients' quality of life. Recently,
guselkumab, a
monoclonal antibody against
IL-23, has been available for the treatment of PPP in Japan. The purpose of the present review is to describe the characteristics of Japanese PPP patients and
biologic therapy of PPP/PAO using
guselkumab. Most Japanese dermatologists consider PPP as a distinct entity and co-existence of PPP and
psoriasis is rare. However, outside Japan, PPP is often considered to be palmoplantar
psoriasis, and extra-palmoplantar lesions associated with PPP are regarded as
psoriasis. PPP develops or exacerbates either with or without
arthralgia, following
focal infections, such as
tonsillitis, odontogenic
infection, and
sinusitis. Treatment of
focal infection results in dramatic effects on cutaneous lesions as well as
joint pain. By contrast, we sometimes see patients whose skin/joint symptoms do not improve
after treatment of
focal infection, whose focus of
infection cannot be identified even in a detailed examination, and/or who refuse
tonsillectomy even if strongly recommended. Such cases are considered to be indications of biologics. In this review, clinical features, pathophysiology and
guselkumab therapy are discussed.