Topical corticosteroid phobia is an important problem in the treatment of atopic dermatitis as it can affect the ability to control disease severity and itch by reducing treatment adherence. Topical corticosteroid phobia often ends up even non-corticosteroid adherence. As such, non-corticosteroid adherence, disease severity and itch are likely to be associated with each other, but their relationship has yet to be thoroughly investigated. Thus, the purpose of this study is to investigate it in atopic dermatitis. Using data from 1190 participants in an Internet survey, we identified 255 non-corticosteroid users and 225 with moderate to severe itch who were defined as non-corticosteroid adherents. Corticosteroid users with the same itch categories (n = 878) served as controls. We also examined how itch severity affects the perception of itch in atopic dermatitis. Unexpectedly, non-corticosteroid adherents were less sensitive to the conditions to elicit itch such as perspiring, commuting homeward, drinking alcohol and wearing woolen clothes compared with the control. We also found that patients with severer itch were more sensitive to itch during/after bathing, when lying in bed, commuting homeward, studying/working, drinking alcohol, undressing, getting up in the morning, after a meal, ingesting piquant foods and when they were unoccupied, angry, busy, nervous, sad or enjoying themselves. In conclusion, we found that non-corticosteroid adherence and itch severity influence perception of itch in atopic dermatitis and discuss possible mechanisms underlying these results. The information obtained in this study may be useful for communication with and education of atopic dermatitis patients and their treatment in outpatient clinics.