Objectives: Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are rare, genetic disorders of the heme metabolic pathway that cause cutaneous photosensitivity. Study objectives were to explore the patient experience of living with EPP/XLP and potential benefits of treatment outcomes as part of a vignette health-utility estimation study to quantify the quality-of-life impact of EPP/XLP.

Methods: Semistructured qualitative interviews were conducted with patients recruited from patient organizations, clinicians, and patient advocates in the United States (US) and United Kingdom (UK). Interview data were analysed using content analysis.

Results: 8 EPP/XLP patients (4 US, 4 UK; 4 females; mean [range] age, 38.8 [24-52]; mean [range] time to prodrome, 12.9 [1.5-30] minutes), 2 clinicians, and 2 patient advocates were interviewed. Most frequently reported initial prodromal symptoms after sunlight exposure were tingling (n=10), itching (n=9), and mild burning (n=8). Key symptoms of a full phototoxic reaction were intense burning (n=12) and excruciating, relentless pain (n=11). The reported impact of EPP/XLP was wide reaching, and patients described being in a constant state of alert and anxiety: “...there was always pain and fear and anxiety and then the constant sensation that I was putting other people out, feeling like a burden.” Phototoxic reactions were reported as typically lasting 2‑7 days, during which time patients are completely debilitated. Between reactions, key impacts of living with EPP/XLP included restricted participation in outdoor activities, impaired relationships, social isolation/withdrawal, and detriments to mental health. Perceived potential benefits of 30-90 minutes of additional light tolerance included reduced anxiety; increased freedom to participate in normal, everyday activities; and greater opportunities for life experiences.

Conclusions: The interviews provided key insights into the patient experience of living with EPP/XLP and the wide-reaching detriments to quality of life. Treatments that result in modest increases in light-exposure tolerance have the potential to significantly improve patients’ lives.