Clinical outcome of tonsillectomy for palmoplantar pustulosis and etiological relationship between palmoplantar pustulosis and tonsils.

Palmoplantar pustulosis (PPP) is famous for causing typical tonsillar focal diseases. Clinical improvement of PPP rash after tonsillectomy was seen in 109 (94%) of 116 patients by subjective self-assessment, and 52 (88%) of 59 patients by objective Palmoplantar Pustulosis Area and Severity Index (PPPASI) scoring. Flow-cytometric analyses revealed that expression of activation markers (CD25 and HLA) class II increased on tonsillar T cells from PPP and IgAN patients. Moreover, expressions of skin-homing receptors (CLA and CCR6) increased on tonsillar T cells from PPP patients. In addition, the expressions were enhanced by stimulation of indigenous bacteria. Moreover, those expressions also increased in peripheral T cells, and decreased after tonsillectomy. Immunohistchemical analyses revealed that the ligands of those receptors (E-selectin and chemokine ligand 20) were expressed in lesions of skin. On the basis of our findings, migration of tonsillar T cells on which several homing receptors express by hyperimmune response against indigenous bacteria have a critical role in the pathogenesis of tonsillar focal diseases.