Alopecia areata universalis in Leonardo da Vinci's Mona Lisa: A systematic retrospective iconodiagnosis

The face of Leonardo da Vinci's Mona Lisa (ca 1503-1519) has attracted several medical presentations, most recently the hypothesis of frontal fibrosing alopecia masquerading as Renaissance fashion. I present a systematic retrospective iconodiagnosis grounded in an explicit methodological framework, in the technical literature on the painting, including 13-band multispectral imaging, and in the documented biography of the sitter, Lisa Gherardini (ca 1479-1542). Four reproducible findings are legible on the panel: complete bilateral absence of the eyebrows; complete bilateral absence of the eyelashes; a frontal hairline without a transition zone; and intact, non-scarred periocular and frontal skin. Tested against these findings, Renaissance cosmetic depilation, frontal fibrosing alopecia, secondary syphilis, lepromatous leprosy, telogen effluvium, and trichotillomania each fail on at least one cardinal sign, whereas alopecia areata universalis accounts for all four without exception. The single supraciliary hair detected by multispectral analysis, previously read as the relic of a vanished painted eyebrow, is reinterpreted as a faithfully depicted solitary surviving terminal hair-a recognized expression of incomplete, asynchronous follicular involvement in alopecia areata, illustrated here by a clinical photograph of an 8-year-old patient with an identical finding. The sitter's documented age (24 years in 1503), and biographic stressors are congruent with the early-onset epidemiology of extensive alopecia areata. Limitations of retrospective diagnosis are addressed, and explicit criteria for disproof are also stated. The most contemplated face in Western art is reframed as a dignified Renaissance document of alopecia areata universalis.