Hydroxocobalamin May Improve Symptoms in Rosacea

Syringe for an injection.
Syringe for an injection.
Does intramuscular administration of hydroxocobalamin have a role in addressing flushing and erythema in rosacea?

Intramuscular administration of hydroxocobalamin may immediately improve facial erythema associated with rosacea, according to findings from a study published in the Journal of Clinical and Aesthetic Dermatology.

Researchers reported their findings in 13 patients with rosacea who were treated with hydroxocobalamin, a nitric oxide scavenger, for their persistent facial erythema.

The patients were enrolled from a dermatology clinic in Taiwan from April through June 2021. They received an intramuscular injection of hydroxocobalamin (1 or 2 mg). Participants who had clinical improvement received additional weekly doses of hydroxocobalamin in the following 1 to 3 weeks.

The Clinician Erythema Assessment (CEA) 5-point scale was used to assess clinical erythema severity: 0 (clear), 1 (almost clear), 2 (mild), 3 (moderate), 4 (severe).

The participants (12 women) were aged 20 to 65 years, and their disease duration ranged from 6 months to 30 years. At the first session, the dose of hydroxocobalamin was 1 mg for 11 patients and 2 mg for 2 patients.

Of 13 patients, 12 had significant clinical improvement within 1 hour of injection. The CEA grade decreased significantly from 2.2 ± 0.6 to 1.2 ± 0.4 (P <.001). Among the 12 patients who had their skin surface temperature (SST) documented, the temperature of the right and left cheeks decreased from 36.7°C ± 0.68°C to 36.2°C ± 0.58°C (P =.001) and from 36.7°C ± 0.76°C to 36.2°C ± 0.66°C (P =.001), respectively.

When the SST results were combined for both cheeks, the temperature decreased significantly from 36.7°C ± 0.70°C to 36.2°C ± 0.61°C (P <.001).

After the first treatment session, 4 patients were lost during the follow-up. The other 8 patients with clinical improvement received additional weekly injections of hydroxocobalamin and demonstrated similar rapid improvement with reduced facial erythema and ­flushing lasting 2 to 6 days, it was noted.

No significant side effects or changes in blood pressure were observed during the follow-up of 2 weeks to 4 months.

The investigators noted that their study was not a randomized controlled trial, and the results could have assessor bias.

“In our small series, intramuscular injection of hydroxocobalamin improved facial erythema of rosacea with rapid onset and minimal adverse effects,” stated the study authors. “These results are encouraging, but further studies are warranted to determine the optimal dosage, efficacy of oral form, treatment duration, and long-term therapeutic effect and side effects.”


Huang Y-W, Huang H-P, Hsu C-K, Lee JY-Y. Hydroxocobalamin: an effective treatment for flushing and persistent erythema in rosacea. J Clin Aesthet Dermatol. 2022;15(6):42-45. PMCID: PMC9239126