Got urticaria?


A case report from the USA (New Jersey) was just published that describes a 24-year-old vegan woman who suffered from hives (also known as urticaria) for several years (!). Urticaria presents as an itchy skin rash that appears as flesh-coloured (in people with darker skin) or red bumps (in people with lighter skin colour).
"This report presents a case of chronic urticaria in a vegan patient whose symptoms resolved completely following the correction of a profound vitamin B12 deficiency."

The woman did not have any other health issues, and the urticaria did not disappear after treatment with medication (H1 blockers [antihistamines] and H2 blockers). Testing for autoimmune disease and allergy testing - luckily - showed: no autoimmune disease and no allergies.

They did all kinds of blood tests (including for HIV).

Then they tested her vitamin B12 blood levels and found that her B12 levels were very low: about 170 pg/mL (= 125 pmol/L).

Then they did all kinds of tests to find out what the reason for this vitamin B12 defiency could be, for example, problems with intestinal B12 absorption (unrelated to diet). But there were no such problems.
The reason for the vitamin B12 deficiency was that she had been vegan for quite a while - they do not say how long ("long-standing vegan diet without vitamin supplementation") - and she had not taken a vitamin B12 supplement.

She started taking a vitamin B12 supplement and got injections too ("vitamin B12 supplementation, including sublingual and intramuscular administration"; they do not say how many micrograms) and the chronic urticaria resolved step by step:
  • after 1 week: mild reduction in symptoms
  • after 4 weeks: significant improvement
  • after 8 weeks: full symptom resolution

The authors estimate that, considering all people, the percentage of urticaria cases that are caused by vitamin B12 deficiency is less than 1% ... But this percentage may be much higher among non-B12-supplementing vegans with urticaria.

If you know a vegan with urticaria, please let them know that vitamin B12 deficiency can cause urticaria. (It can cause a very wide - and unpredictable - variety of problems.)


Reference:

Auda H Auda, Oluwasegun Shoewu, Ingrid Corredor, Ayrton Bangolo, Mohammad Jurri, John Sotiriadis, Iyad Baker: Resolution of Chronic Urticaria in a Vegan Patient With Vitamin B12 Supplementation: A Case Report. J Community Hosp Intern Med Perspect. 2025 May 5;15(3):108-110. doi: 10.55729/2000-9666.1492. eCollection 2025. https://pubmed.ncbi.nlm.nih.gov/40755988/





Pruritus