We report a case of generalized familial benign chronic pemphigus (FBCP) whose generalized condition was induced by an infection by Pseudomonas aeruginosa. A 34‐year‐old male suffered erythemato‐macerative lesions over most of his body. Upon microbiological examination, Pseudomonas aeruginosa was cultured from the pus of the lesions. Histologically, a specimen from the abdominal lesion revealed typical features of familial benign chronic pemphigus. It is well known that FBCP is exacerbated by topical infection. We supposed that, in this case, the infection by Pseudomonas aeruginosa was induced by inappropriate therapy with cortiosteroid. Topical application of silversulfadiazin cream was effective in improving the generalized lesions of this condition.