JMIR Publications

This study investigates the clinical characteristics of Hell's Itch (HI), a poorly understood condition triggered by UV exposure, and its comparison with Aquagenic Pruritus (AP), a condition marked by severe itching after water exposure. These conditions share the inciting event of water exposure and differ from other photosensitive disorders given their typical lack of skin changes outside of the preceding sunburn changes seen in HI patients. Through cross-sectional surveys conducted within HI and AP communities (N=671 and N=254, respectively), we analyzed symptom occurrence and severity and skin changes immediately before and after symptom onset. Results revealed both conditions shared similar pruritus severity, but a significant difference in pain severity, with HI participants reporting more intense pain (92.23%, severity 7.45) compared to AP (39.91%, severity 6.35, P=.0003). The majority of individuals in each condition experienced no visible skin changes (HI: 366 (50.27%), AP: 202 (81.12%)) though this finding was statistically significant. The findings suggest potential shared pathogenic mechanisms between HI and AP, highlighting the need for further research to improve diagnosis and treatment strategies for these conditions.