Atopic dermatitis (AD) presents as a prevalent chronic, relapsing, inflammatory skin condition. While dupilumab has proven effective in treating moderate-to-severe AD, some patients still experience unsatisfactory outcomes with this therapy in clinical settings. Patients with AD receiving dupilumab were selected for inclusion in the present study for prospective observations. Over an 8-week period, the patients underwent monitoring and changes in serum biomarkers and circulating T helper (Th) cell levels were analyzed using questionnaires, ELISA and flow cytometry. The Scoring Atopic Dermatitis (SCORAD), Objective-SCORAD, Itch Numeric Rating Scale (NRS), Dermatology Life Quality Index, Patient Oriented Eczema measure and Atopic Dermatitis Control Tools scores in patients with AD significantly decreased at week 8 compared with those before treatment (P<0.05). Moderate positive correlations were demonstrated between serum thymus and activation-regulated chemokine (TARC) and human β-defensin 2 levels and Eczema Area and Severity Index (EASI) and SCORAD scores (P<0.05). A weak negative correlation was shown between serum IgE against enterotoxin A level and the EASI and SCORAD scores, although these were not statistically significant (P>0.05). There was a notable increase in the proportion of Th2 cells in peripheral blood at week 2 (P<0.05). The proportion of Th22 cells in the peripheral blood was weakly correlated with the NRS score (P>0.05). Patients were categorized into rapid or slow groups depending on whether they achieved EASI-75 scores by week 8. The proportion of Th17 cells in peripheral blood in the rapid group at week 8 of treatment was lower than that compared with the slow group at week 2 (P<0.05). The SCORAD scores of the rapid group were significantly lower compared with those of the slow group at week 8 of treatment (P<0.05). The conventional dupilumab treatment regimen led to a marked remission in patients with exogenous AD after 8 weeks of therapy. Significant correlations were observed between serum TARC levels and clinical disease scores (P<0.05), which changed notably during treatment and remained valuable for monitoring disease progression at follow-up. Additionally, the elevated ratio of Th17 cells in peripheral blood at week 2 of treatment showed potential for predicting the attainment of EASI-75 by week 8 after treatment.