Yağmur Karakoç, Nadide Yıldız, Hilal Aksoy, İzzet Fidancı, Duygu Ayhan Başer
Ankara Medical Journal - 2025;25(4):467-472
Objectives: Vitamin B12 deficiency is a common condition encountered in primary care, typically resulting from inadequate dietary intake. Intramuscular B12 replacement therapy is widely used and generally considered safe; however, it may rarely cause dermatological adverse effects, particularly acneiform eruptions. We report the case of a 26 -year -old female patient who received intramuscular cyanocobalamin for five consecutive days to correct B12 deficiency . In the second week of treatment, she developed non -pruritic papulopustular eruptions, initially appearing on the back and chest and subsequently spreading to the face and neck. The clinical presentation was consistent with a vitamin B12 -induced acneiform eruption. This case highlights the need for primary care physicians to be aware of this rare adverse effect and emphasizes the importance of early recognition and appropriate management.
