Background/Purpose This is a prospective study analysed the incidence of skin cancer (SC) (melanoma and non-melanoma SC) in 90 adult patients affected by Systemic Lupus Erythematosus (SLE), followed-up in one single Rheumatological Center, compared with 54 patients affected by Systemic Sclerosis (SSc) and 90 sex- and age-matched 90 control subject.

Methods In a period between February and July 2019, every patient underwent a complete dermatological evaluation and filled out a questionnaire regarding their personal or family history of SC, the presence of different risk factors of SC and the occurrence of photosensitivity.

Results 90 SLE patients (96,7% female, mean age: 44 years; range: 18–78) showed photosensitivity in 60%

63% of patients avoided sun exposure at every hour of the day, 80% used photoprotection and 28% referred systemic worsening of SLE features after sun exposure. No new onset skin cancer was diagnosed.

Three SLE patients referred a history of SC (1 basalioma, 1 melanoma, 1 multiple actinic lesions) onset after the SLE diagnosis. Patients with skin cancer (SC+) didn’t show any differences compared with patients without skin cancer (SC-) except for more frequent photodamage features (p: 0.032) and less frequent photosensitivity (0.031).

SLE patients more frequently showed photosensitivity (p<0.0001), photoprotection (p<0.0001), disease worsening and skin worsening after sun exposure (p: 0.033 and 0.002, respectively) compared with SSc cases. No differences in past history of SC was evident between groups.

Comparing SLE with age-, sex- and phototype-matched control cohort, SLE patients showed a lower rate of past history of basalioma skin cancer (p: 0.013), lower rate of photodamage (0.027) and higher rate of photosensitivity (p<0.0001).

Conclusions SLE patients showed a significant lower rate of skin cancer, despite a higher rate of photosensitivity, compared with control cohort. This data could be due to a strict and continued photoprotection.