BACKGROUND: Atopic dermatitis (AD) and asthma often coexist. Both diseases can have a major impact on the lives of children with AD and their caregivers. AIM: To investigate the association of patient characteristics, comorbidities and impact of AD on children who have both asthma and AD. METHODS: Children with AD (n = 140) were selected from a larger cohort of children with a reported use of asthma medication. The Children's Dermatology Life Quality Index (CDLQI) was used to assess Quality of Life (QoL), and the Self-Assessed Eczema Area and Severity Index (SA-EASI) was used to measure AD severity. Characteristics assessed included: age, sex, and the number and type of atopic comorbidities. Medication use for AD was defined using the total number of AD prescriptions, the number of different topical AD prescriptions and the highest potency topical corticosteroid (TCS) used. Determinants of AD severity and QoL were evaluated using Spearman rank tests. RESULTS: The following factors were most strongly associated with a lower QoL: characteristics of AD lesions (Spearman Rs= 0.61-0.69, P < 0.01), a higher SA-EASI score (Rs= 0.54, P < 0.01) and a larger number of different topical AD prescriptions (Rs= 0.38, P < 0.01). The following factors were correlated with more severe AD: age (Rs= -0.36, P < 0.01), larger number of different TCS preparations used (Rs= 0.27, P < 0.05) and larger number of TCS prescriptions (Rs= 0.25, P < 0.05). CONCLUSION: In children with asthma and AD, the number of TCS preparations used is associated with lower QoL and increased AD severity