Cutaneous immune-related adverse events: incidence rates, risk factors and association with extracutaneous toxicity - a prospective study of 189 patients treated with checkpoint inhibitors at a Spanish tertiary care hospital.

BACKGROUND: Clinicians are increasingly prescribing immune checkpoint inhibitors (ICIs) to treat cancer, but the real-world incidence, characteristics and risk factors of cutaneous immune-related adverse events (cirAEs) are unclear. OBJECTIVES: To determine the incidence, features and risk factors of cirAEs and to measure their possible association with extracutaneous toxicity. METHODS: We conducted a prospective observational study in a Spanish tertiary care hospital, including people who started an ICI between March 2020 and May 2022. We used a survival analysis and a log-rank test to obtain and compare incidence rates, and a multivariate Cox model to detect risk factors for cirAEs. RESULTS: We included 189 patients, 82 (43.4%) of whom presented cutaneous toxicity. The incidence of cirAEs was 75.0 per 100 person-years, with a 50.0% probability of the appearance of a cirAE at 10 months of follow-up. The most frequent cirAE category was inflammatory dermatoses, and the most frequent types were pruritus, eczema and maculopapular eruptions. ICI combination therapy, a family history of psoriasis and rheumatological and pulmonary immune-related adverse events increased the risk of cirAEs. CONCLUSIONS: We found a high incidence of cirAEs, and they occurred early in the follow-up period. Dermatologists should be involved in the management of cirAEs, especially in people with risk factors.

Atypical pediatric presentation of lymphocytic thrombophilic arteritis: Diagnostic difficulties and recent nosological clarification.

A 4-year-old girl presented with a 2-month history of round, hypopigmented, slightly scaly patches measuring 1-6 cm and encircled by an erythematous halo, first appearing on the lower limbs then spreading to the whole body. Three biopsies were taken as the condition progressed, each showing a lymphocytic infiltrate affecting a medium-sized artery at the dermal-subcutaneous junction, with a concentric fibrin ring. These findings are characteristic of lymphocytic thrombophilic arteritis (LTA). The young age of our patient and the type of skin lesions she developed make this an atypical presentation of LTA, which usually manifests as hyperpigmented macules on the lower extremities, predominantly in dark-skinned women.