A total of 1507 adults and 525 children, who responded to the October 2022 kencom app questionnaire reported a diagnosis of AD and experienced either symptoms or ongoing treatment within the previous 6 months, were included in the study (Fig. 1).

Selection of participants

Among adults with AD, the mean age was 46.2 years (SD, 10.5) and 53.7% were male. Among children, the mean age was 10.8 years (SD, 5.1) and 54.1% were male (Table 1).

Comorbid bronchial asthma and allergic rhinitis were reported in 10.0% and 23.7% of adults, respectively, and in 12.0% and 18.5% of children, respectively (Table 1). Most participants had received treatment for AD within the previous 6 months, with prescription therapy alone being the most common treatment modality (in 70.0% of adults and 85.7% of children). A smaller proportion received only nonprescription treatment, including over-the-counter or traditional medicines (in 12.5% of adults and 5.3% of children), while 15.1% of adults and 6.7% of children reported receiving no treatment during this period.

Among adults, the mean POEM score was 7.3 (SD, 6.7) and the median score was 6.0 (IQR, 2.0–11.0). Based on POEM severity bands, 30.1% of adults (n = 453) had AD classified as clear or almost clear, 29.1% (n = 439) had mild AD, 29.2% (n = 440) had moderate AD, and 11.6% (n = 175) had severe or very severe AD (Fig. 2).

Association between POEM severity bands and habitual scratching among adults (n = 1,507). aCochran–Armitage test. POEM Patient-Oriented Eczema Measure

Among children, the mean POEM score was 5.2 (SD, 5.4), and the median was 4.0 (IQR, 1.0–8.0); 40.2% (n = 211) had AD classified as clear or almost clear, 33.5% (n = 176) had mild AD, 21.9% (n = 115) had moderate AD, and 4.4% (n = 23) had severe or very severe AD (Fig. 3).

Association between POEM severity and habitual scratching among children (n = 525). aCochran–Armitage test. POEM Patient-Oriented Eczema Measure

Responses to questions on habitual scratching revealed that 44.5% of adults (n = 670) reported scratching even when they did not feel itchy and 30.0% (n = 452) reported becoming aware of scratching only when it was pointed out by someone else. Among children, these proportions were 57.5% (n = 302) and 53.3% (n = 280), respectively (Table 2).

In both adults and children, the proportion of participants who answered “yes” to each question on habitual scratching had increased with greater AD severity, as assessed by POEM. Among adults, the proportion who reported scratching despite the absence of itch ranged from 35.1% in the clear/almost clear group to 62.9% in the severe/very severe group (Fig. 2A). Proportions of adults who only became aware of scratching when it was pointed out by someone else ranged from 19.0% to 50.3% (Fig. 2B). In both cases, the Cochran–Armitage test indicated a statistically significant association with POEM severity bands (p < 0.001).

A similar pattern was observed in children. The proportion of participants who reported scratching even when they did not feel itchy rose from 44.5% in the clear/almost clear group to 82.6% in the severe/very severe group (Fig. 3A). Similarly, the proportion of participants who reported becoming aware of scratching only when it was pointed out by someone else increased from 41.2% to 69.6% (Fig. 3B). In both cases, the Cochran–Armitage test indicated a statistically significant association with POEM severity bands (p < 0.001).