The Significant Role of Atopic Skin Diathesis in Prurigo Nodularis.

Objectives: Atopic skin plays a significant etiological role in the development of prurigo nodularis (PN). In addition to atopic dermatitis (AD), atopic skin diathesis without eczema can also contribute to the development of PN due to its association with itching. This study aims to evaluate PN in terms of AD/atopic skin diathesis, associated comorbidities, and clinical findings.

Methods: Patients diagnosed with PN based on clinical and histopathological findings between 2014 and 2024 were included in the study. Associated diseases that could contribute to the etiology of pruritus were recorded as comorbidities. The diagnosis of AD was evaluated using the Hanifin-Rajka's diagnostic criteria and atopic skin diathesis using the Erlangen Atopy Score. Patients were classified as atopic and non-atopic groups, and these groups were compared in terms of demographic and clinical findings.

Results: The study included a total of 47 patients, of whom 15 (31.9%) were male and 32 (68.1%) were female. At least one comorbidity was identified in 89.4% (n=42) of the patients, and multiple comorbidities were found in 34% (n=16). Atopic dermatitis and/or atopic skin diathesis were present in 55.3% (n=26) of the patients. Among these, 53.8% (n=14) were diagnosed with AD, while 46.2% (n=12) had only an atopic skin diathesis. Compared to the non-atopic group, the atopic group had a lower median age (p=0.001) and higher serum total IgE levels (p=0.031).

Conclusion: In addition to AD, atopic skin diathesis without eczema also appears to play an important role in the etiology of PN. The lower age and higher IgE levels in patients are factors associated with atopic predisposition.