Abnormal photosensitivity may be obvious clinically and there may be no need for photodiagnostic investigations, as with typical polymorphic light eruption. However, photosensitivity is frequently not considered as a possibility, either by the patient, their Primary Care physician or their dermatologist, leading to missed or delayed diagnosis. Accurate diagnosis is essential to advise patients and physicians regarding appropriate management, and photosensitivity diseases are a diverse group of conditions, with heterogeneity in clinical presentations and photodiagnostic findings.
Investigation through narrow waveband ultraviolet (UV) and visible light testing, such as with the use of a monochromator, provides objective evidence of the action spectrum for induction of abnormal photosensitivity, and can facilitate evaluation of treatment outcomes and the natural history of the condition. Supplementary investigations with broader band iterative UV provocation testing, patch and photopatch testing, and screening for conditions such as lupus and the cutaneous porphyrias, can enable a comprehensive diagnosis to be made. The British Photodermatology Group/British Association of Dermatologists reviewed the provision of photodiagnostic services in the UK. This highlighted the diversity of photosensitivity diseases and the complexities and challenges of investigations, and attempted to initiate a consensus approach between Centres.
However, it is recognised that there is a paucity of photodiagnostic services worldwide, and raising awareness of photosensitivity conditions and the key components of photodiagnostic services, is important for accurate diagnosis and management. This is essential as the major adverse impact of photosensitivity on patients’ lives is increasingly recognised, and the provision of support through patient-centred care is a priority.
New developments in photodiagnostic techniques, with advances in LEDs and refinement of existing investigations such as photopatch testing, aim to improve accessibility, ease and efficiency of photodiagnostic services, and this presentation will shed further light on the role of photodiagnostics in the management of patients with photosensitivity diseases.