Canities Subita After Extreme Trauma Showing Positive Staining for Anti-PD-L1 Antibodies: A New Clue Into Etiopathogenesis?

A case report described a 69-year-old man who experienced sudden hair whitening, known as canities subita, following the traumatic event of his brother's death. This condition was characterized by the rapid whitening of scalp and eyebrow hair without significant hair loss. The patient had a history of alopecia areata, which had resolved spontaneously. Histopathological analysis revealed a lymphocytic inflammatory infiltrate and positive staining for anti-PD-L1 antibodies, suggesting an immune-mediated mechanism. These findings indicated a potential link between the immune system and the sudden loss of hair pigmentation, highlighting the need for further research into the interaction between melanogenesis and lymphocytes in canities subita.