Skin dryness, dust exposure, and emotional stress were identified as correlates of pruritus in adults with atopic dermatitis (AD) according to study data published in Advanced Experimental Medicine and Biology.

Adults with AD were recruited to participate in this study at a research university in Poland. Patients were asked to assess their pruritus in the past 24 hours using a 10-point Visual Analogue Scale, with higher numbers denoting greater itch severity. Blood samples were also taken and assessed for specific immunoglobin E (sIgE) antibodies against dust mites, grass, and weeds. IgE antibody levels were classified as follows: Class I (0.35–0.69 IU/mL), Class II (0.70–3.49 IU/mL), Class III (3.50–17.49 IU/mL), Class IV (17.50–49.90 IU/mL), Class V (50.00–100.00 IU/mL), or Class VI (>100 IU/mL). Greater classes represented greater reactivity to the specified allergens. Blood samples were also assessed for interleukin (IL)-33 levels and compared with results from a control sample of 20 adults. Patients were then asked to name their top 5 itch-aggravating factors on a self-report questionnaire which listed 15 common irritants.

The study cohort comprised 34 adults with AD, of whom 18 (52.9%) were women. Median age was 40 years (range, 20-70). Nearly all patients (94.1%) had a disease duration exceeding 10 years, and 88.2% reported consistent symptom worsening over time. Median SCORing Atopic Dermatitis (SCORAD) index score was 60.6 points (range, 50.2-80.4 points), denoting “severe” disease. All patients evaluated their pruritus as a 9 or 10 on the Visual Analogue Scale. The most commonly cited itch aggravators were dry skin (n=27; 79.4%), contact with dust (n=22; 64.7%), and emotional distress (n=17; 50.0%). Patients who listed dust as an aggravating factor were more likely to have Class V or Class VI levels of sIgE antibodies to dust mites than patients who did not (95.5% vs 33.3%; P <.001). No other significant correlations were observed between self-reported itch aggravators and sIgE levels. However, IL-33 levels were significantly higher in patients with AD (median, 173.4 pg/mL) than in healthy control patients (median, 77.0 pg/mL) (P <.001).

These data highlight the biochemical and psychological aggravators of pruritus in patients with severe AD, the researchers believe. Itching was strongly correlated with skin dryness, contact with dust mites, and self-reported emotional distress. Efforts to mitigate all 3 of these factors may be important to reducing itching in AD. Data generalizability are limited by the small cohort size; replication in a larger group is necessary to further elucidate correlates of pruritus in AD. “This report summarizes our practical knowledge concerning the causative factors of exacerbations of skin lesions in adult atopic dermatitis, pointing to possible preventive interventions,” investigators wrote.


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Reference

Jaworek AK, Szafraniec K, Doniec Z, Jaworek M, Wojas-Pelc A, Pokorski M. Pruritus characteristics in severe atopic dermatitis in adult patients [published online June 27, 2020]. Adv Exp Med Biol. doi: 10.1007/5584_2020_548