The addition of topical antibiotics to topical corticosteroids (TCS) did not provide additional clinical improvement in infants with moderate to severe atopic dermatitis (AD) during a short-term follow-up period; yet, the addition of antibiotics did appear to reduce skin commensal Streptococcus bacteria, according to study results published in Dermatologic Therapy.

This study included children younger than 2 years of age with moderate to severe AD who were admitted to a dermatology department at a hospital in China. Investigators randomly assigned patients to either TCS mometasone (n=21) or a combination regimen consisting of mometasone plus topical antibiotic mupirocin (n=38).

Patients were prescribed these therapies for twice-daily use. Researchers defined clinical recovery as the achievement of a SCORing Atopic Dermatitis (SCORAD) score of <25 after 2 weeks of treatment.

A total of 57 patients experienced significant clinical improvement and a decreased SCORAD index of <25. Investigators found no difference between the 2 groups with regard to clinical improvement. They also observed no differences in the groups in terms of bacterial diversity from pretreatment to posttreatment.


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Patients treated with the combination approach experienced a significant decrease in the abundance of Staphylococcus from 2.29% before treatment to 0.57% after treatment (P <.001). In addition, S aureus decreased from 2.24% to 0.53% (P <.001). Treatment with TCS was associated with a pretreatment to posttreatment increase in S aureus of 2.08% to 33.47%, respectively. Likewise, Streptococcus accumulated from 2.11% to 39.37% after just 2 weeks of treatment with TCS.

In 1 patient who received combination therapy, the alpha diversity Shannon index decreased from 3.68 to 3.18. Also, commensal Streptococcus and opportunistic pathogen Pseudomonas increased after treatment, as did Chryseobacterium, to 35.09%, 4.84%, and 7.95%, respectively. In another patient, approximately 94.3% of cutaneous microbiota at baseline was represented by an abundance of S aureus, which reduced to 4.29% after treatment with TCS. Researchers observed significant increases in commensal Streptococcus and alpha diversity after a 2-week protocol of TCS in this patient.

Limitations of the study included the lack of long-term follow-up and the lack of assessment of antibiotic use in patients with other cutaneous microbiota profiles.

The researchers concluded that their “preliminary findings indicated the necessity to consider cutaneous microbiota in medication of AD patients in infancy.”

Reference

Liu Y, Zhou Q, Dai W, et al. Is antibiotics prescription needed in infants with topical corticosteroids treatment for moderate-to-severe atopic dermatitis? [published online August 22, 2020]. Dermatol Ther. doi: 10.1111/dth.14215