- Abstract Background Following a case of serologically proven hepatitis A in a food-handling worker serving several military bases in the same vicinity, the entire military population was vaccinated with immune serum globulin (ISG). Objective To evaluate the effectiveness of ISG in preventing skin disease. Methods The data for this study were drawn from the military archives of the Medical Corps. The population of the bases was followed for a period of 3 months after immunization. Rates of selected skin diseases were compared with those of a nearby base during the same period, and with those in the population of the same bases a year earlier. Results The rates of several skin diseases (bacterial skin infections, dermatitis and eczema, fungal infections, acne, warts, nail disorders, and nonspecific skin diseases) among the vaccinated population were significantly lower when compared to the historical control group and to the contemporary control group of the nearby base. Conclusions ISG provides a protecting effect for skin diseases, especially those of infectious origin.