SAN DIEGO – Patients with atopic dermatitis should routinely receive the intramuscular form of the influenza vaccine Fluzone unless the affected area of skin has been swabbed and found to have normal skin flora, data from a controlled study suggested.
"The original studies leading to approval of intradermal vaccination with Fluzone were done only in normal subjects," Dr. Donald Y.M. Leung said in an interview prior to the annual meeting of the American Academy of Allergy, Asthma, and Immunology, where the findings were presented. "Patients with atopic dermatitis [AD], the most common skin disease in the general population, were not included in previous studies. AD patients are prone to skin infection and may have an abnormal immune response in their skin."
Dr. Donald Y. M. Leung
To determine whether patients with AD had a normal skin immune response to Fluzone, Dr. Leung and his associates at five medical centers measured hemagglutination inhibition antibody (HAI) titers at baseline and 28 days post vaccination in 223 subjects with AD (including a subset with Staphylococcus aureus colonization) and 135 nonatopic controls after administration per label of either a single dose of the seasonal 2012-2013 intradermal Fluzone or Fluzone for intramuscular injection. They excluded subjects who were seroprotected at baseline (defined as an HAI of greater than 1:40).
Dr. Leung, who heads the division of pediatric allergy and immunology at National Jewish Health, Denver, reported that seroprotection and seroconversion rates for the three influenza strains included in the vaccine (B, H1N1, and H3N2) were not significantly different for AD and control subjects who received intradermal vaccination. Seroprotection and seroconversion rates were similar for AD subjects who received intradermal vaccination compared with AD subjects who received intramuscular vaccination.
Following intradermal vaccination, AD patients colonized with S. aureus had notably lower seroprotection and seroconversion rates to the B strain (12% vs. 47%, P less than .001, and 21% vs. 51%, P = .002, respectively) and a lower seroconversion rate for H1N1 (77% vs. 95%, P = .029) compared with subjects with uncolonized AD. There were no notable differences for H3N2. No differences were observed between AD subjects colonized with S. aureus and uncolonized AD subjects following intramuscular Fluzone for any strain.
"Although the AD group as a whole had a normal response to Fluzone given in the skin, the large subset of AD patients who were colonized with Staphylococcus aureus had a reduced response to Fluzone vaccination when the vaccine was introduced into the skin as opposed to the conventional intramuscular injection," Dr. Leung said. "Studies are needed to find out why colonization of the skin with S. aureus is associated with reduced skin immune responses."
The study was funded by the National Institute of Allergy and Infectious Diseases. Dr. Leung said he had no relevant financial conflicts to disclose.