The Validity and Reliability of Patient-provided Photographs for Diagnosing and Assessing the Severity of Hand Eczema.

Hand eczema (HE) is a common skin disease, diagnosed through clinical evaluation. However, the increasing need to deliver healthcare remotely, along with the demand for valid and reliable evaluations of HE in research, prompts exploration of the potential benefits of remote assessment. This study assessed the criterion validity and inter- and intra-rater reliability of patient-provided photographs to diagnose and assess the severity of HE. The presence and severity of HE were assessed by 1 of the 2 clinical raters. Following instructions, patients took 4 photographs of their hands. All photographs were assessed twice by the clinical raters and 2 additional raters. In total, 98 patients were included. The sensitivity, specificity, positive and negative predictive value were respectively 85.1%, 79.2%, 92.6%, and 63.3%. Kappa values of 0.35 and 0.66 were found for inter- and intra-rater reliability. The intraclass correlation coefficients based on the Hand Eczema Severity Index (HECSI) were > 0.90. Kappa values for the criterion validity and inter- and intra-rater reliability using the photographic guide were respectively 0.71, 0.58-0.77, and 0.77. The findings indicate that patient-provided photographs are valid and reliable for remote assessment of HE and could be of benefit in healthcare and research by reducing in-person visits and enabling continuous monitoring.