photosensitivity

https://doi.org/10.1351/goldbook.13570
Skin reddening due to an abnormal reaction to sunlight, characteristic of systemic autoimmune diseases [e.g., systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD)], and cutaneous and subacute cutaneous lupus erythematosus.
Source:
PAC, 2012, 84, 1113. (IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)) on page 1229 [Terms] [Paper]