This study aimed to identify risk factors and combinations thereof that are associated with severe skin injuries due to the extravasation of injectable drugs. A cross-sectional study using the Japanese Adverse Drug Event Report database was conducted according to the RECORD-PE checklist. Adverse event reports related to necrosis, ulcers, or erosions due to extravasation were considered “with severe skin injury,” and others were considered “without severe skin injury.” Approximately 255 cases “with” and 260 cases “without” severe skin injury were identified. The relationship between the incidence of severe skin injury and age, sex, drugs, and primary disease was evaluated using the χ2 test. Association rule mining was used to evaluate the correlation between each combination of factors and skin injury. Nine factors were identified as independent risk factors for severe skin injury, including age (<10 or ≥70 years), peripheral parenteral nutrition use, and mental disorders. The association rule mining results suggested that a combination of specific patient backgrounds and drug use was associated with the incidence of necrosis or ulcers. The findings of this study reiterate that nurses might consider closely observing patients with the risk factors identified in this study for the prevention and early detection of extravasation-related skin injuries.