Smartphone Photographs of Chronic Urticaria Taken by Patients Are of Good Quality and Useful in the Clinic

Background: Chronic urticaria (CU) is characterized by transient wheals and angioedema, which are often not present when patients see their treating physician. Objective: The objective of this study was to evaluate the diagnostic value of smartphone photographs captured by patients prior to their first visit at an urticaria outpatient clinic. Methods: A survey regarding the quality and utility of smartphone photographs of urticarial skin lesions in patients with CU attending the outpatient clinic for the first time was conducted. Up to three random patient-selected photographs of skin lesions were evaluated by a physician. Results: Of 148 patients, 118 (79.7%) had taken photographs of their skin lesions prior to the consultation, and 75% took photographs with the intention of presenting it to their physician. The photographs were of wheals in 90% of the cases and angioedema in 8%. In total, 72% of the smartphone photographs had the skin lesion in focus, 64% had good resolution, and 48% had good lighting. Only 9% of the smartphone photographs were blurred, 10% had bad lighting, 4% had bad resolution, and 8% did not have the lesion in focus. Moreover, 86% of the smartphone photographs were found to be useful for clinical evaluation. At least one photograph of good/very good quality was presented by 86% of the patients, and 97% had at least one photograph that was useful for clinical evaluation. Conclusion: Patients with CU often take smartphone photographs of their skin lesions on their own initiative prior to their first consultation to present the photographs to their physician. These smartphone photographs are very often of good quality and suitable for clinical evaluation.