NCT02585986.

Methods	Randomised double‐blind placebo‐controlled clinical trial
Participants	Children of both genders between 4 and 17 years of age. Estimated enrolment: 50. Country: Spain Inclusion criteria: 4 to 17 years of age Diagnosis of atopic dermatitis according to Hanifin and Rajka diagnostic criteria for atopic dermatitis SCORAD score ranging from 20 to 40 Using topical corticosteroids to treat atopic dermatitis flare‐ups Parent or legal representative has signed informed consent. If the patient is 12 years old or older, the patient must sign a consent to enter the trial Exclusion criteria Pregnancy Breastfeeding Women of childbearing age who do not make a commitment to use any effective contraceptive method Phototherapy treatments for atopic dermatitis Systemic corticoid therapy in the last 2 months Immunosuppressive or cytostatic treatment in the last 2 months Probiotic treatment in the last 2 months Systemic antibiotic in the last 4 months Fever (axillary temperature > 37°C or equivalent) Severe allergic disease Immunodeficiency or cancer‐related processes Other dermatological pathologies that could make the atopic dermatitis evaluation difficult, or that require continued use of topical corticosteroids Any contraindication to any product or drug used during the trial, according to technical files Participation in any drug clinical trial in the last 3 months
Interventions	Dietary supplement: probiotic ‐ daily intake of 1 capsule. Freeze‐dried powder: 10⁹ CFUs of Bifidobacterium lactis CECT 8145, Bifidobacterium longum CECT 7347, and Lactobacillus casei CECT 9104 and maltodextrin Dietary supplement: placebo ‐ daily intake of 1 capsule containing maltodextrin Duration of intervention: 12 weeks
Outcomes	Primary outcome measures Time of use of topical corticosteroids (time frame: 12 weeks) Variation in SCORAD score during treatment (time frame: 12 weeks) Secondary outcome measures Variation in the Global Clinical Impression (CGI) score during treatment (time frame: 12 weeks) Exposure to other treatments (time frame: 12 weeks) Duration of treatment with systemic corticosteroids or antihistamine drugs Side effects due to treatment in 2 treatment arms (time frame: 12 weeks)
Notes	Current status: results published Registration: NCT02585986 (ClinicalTrials.gov). Sponsor: Biopolis SL