Palmoplantar pustulosis: an autoimmune disease precipitated by smoking?

Ninety-five percent of patients with palmoplantar pustulosis are smokers at onset of the disease. The aim of this study was to determine whether these patients have serum antibodies to nicotinic acetylcholine receptors (nAChR ab) and if their sera induce a specific immunofluorescence in normal palmar skin. Sera from 45 patients with palmoplantar pustulosis and 23 patients with chronic hand eczema were analysed for muscle nAChR ab, and immunofluorescence was performed on healthy palmar skin. Forty-two percent of the patients with palmoplantar pustulosis but none of the eczema patients had raised levels of nAChR ab. Immunofluorescence showed staining on endothelial cells in the papillary dermis in 47% of all sera from patients with palmoplantar pustulosis and in those with nAChR ab in 68%. On palmar skin from smokers there was also a staining of the sweat duct. Sera from patients with chronic hand eczema were negative. Our findings indicate that palmoplantar pustulosis is an autoimmune disease, possibly induced by smoking.