Acute generalized exanthematous pustulosis is a severe, life-threatening, drug-induced cutaneous eruption that is associated with appearance of non-follicular sterile pustules on an erythematous base usually with oedema. We report a case of acute generalized exanthematous pustulosis induced by ofloxacin given for acute diarrhea. The patient was then treated successfully with oral glucocorticosteroids. However, what was notable was that he developed linear non-follicular pustules on the back indicating an isomorphic response (Koebner phenomenon) in acute generalized exanthematous pustulosis, which has not been reported before in the published English literature.