ハンセン病に対する多剤併用療法（MDT）において使用されるDDS（ジアフェニルスルホン）、リファンピシン、クロファジミンは、治療効果が高い一方で、重篤な薬疹を引き起こすことがある。特に薬剤性過敏症症候群（DIHS）やスティーブンス・ジョンソン症候群（SJS）/中毒性表皮壊死症（TEN）などの重症型薬疹の発症例が報告されており、治療の継続と副作用対策のバランスが課題である。本稿では、これら薬剤による重症薬疹の臨床的特徴、病態、治療方針について解説し、さらに近年注目されている除菌療法後皮疹の新たな免疫機序についても触れることで、薬疹の多様な発症機構とその臨床的意義を再考する。

  This mini-review explores the evolution and challenges of medical ethics in the context of infectious diseases, spanning from Hansen’s disease (leprosy) to the COVID-19 pandemic. The paper begins by outlining the foundations of medical ethics as both applied ethics and professional ethics, rooted historically in the Hippocratic Oath. It then traces how modern medical ethics have expanded beyond individual clinical care to encompass broader societal responsibilities, especially through the development of epidemiology and public health in the 19th century. The influence of utilitarianism, eugenics, and historical atrocities—such as Nazi medical crimes—shaped the emergence of key ethical principles, including respect for patient autonomy. Landmark declarations such as the Nuremberg Code and the Declaration of Helsinki institutionalized these principles, culminating in the “four principles” framework widely used today: respect for autonomy, non-maleficence, beneficence, and justice. A fictional case study involving a pregnant woman with COVID-19 is analyzed using this framework, highlighting the ethical tensions between individual patient care and institutional or societal health risks. The analysis underscores the importance of comprehensive risk assessments and careful deliberation on fairness and justice in decision-making processes. The paper further investigates the limitations of applying clinical ethical principles to public health contexts, where collective interests often conflict with individual rights. Four distinct categories of public health ethical principles are introduced: minimization of individual liberty restrictions, maximization of population health, procedural justice, and reciprocity. These are contextualized within historical and contemporary infectious disease responses, including controversial policies such as forced isolation, vaccine mandates, and expedited drug approvals. Ultimately, the author emphasizes the unresolved ethical tension between clinical medicine’s focus on individual patient welfare and public health’s emphasis on collective well-being. The article calls for a nuanced ethical discourse that recognizes this dichotomy and advocates for balanced, context-sensitive decision-making during public health crises.