Vitamin B12 induced acneiform eruption

A 47-year-old, north african, male patient, has recently been diagnosed with pernicious anemia, treated with weekly intramuscular hydroxocobalamin. 6 weeks after its initiation, the patient presented a sudden, extensive and monomorphic eruption of inflammatory papulo-pustules and nodules, affecting the face, and the trunk. The eruption was pruritic, and comedones were also present, on the chest. The patient was diagnosed with vitamin B12-induced acneiform eruption. Levels of vitamin B12 were normalized. Hydroxocobalamin was therefore stopped and lymecycline was started, allowing a complete resolution of the lesions within 3 months. Drug intake, sudden and uncommon age of onset, pruritus, a monomorphic pattern and an involvement of extra-seborrheic areas are features that distinguish acneiform eruptions from acne vulgaris.

Automated summary

A 47-year-old north african male patient with pernicious anemia developed a vitamin B12-induced acneiform eruption after 6 weeks of intramuscular hydroxocobalamin treatment. The eruption was sudden, extensive, and monomorphic, affecting the face and trunk, with associated pruritus and comedones on the chest. Discontinuation of hydroxocobalamin and initiation of lymecycline resulted in complete resolution of the lesions within 3 months. The characteristics distinguishing acneiform eruptions from acne vulgaris include drug intake, uncommon age of onset, pruritus, monomorphic pattern, and involvement of extra-seborrheic areas.