Coexistence of Alopecia Areata and Fixed Drug Eruption: An Uncommon Isotopic Phenomenon?
January 2026
TLDR A rare skin reaction occurred when a man took paracetamol, causing a new rash in an area already affected by hair loss.
This article presents a rare case of a 40-year-old man who developed a fixed drug eruption (FDE) within an active alopecia areata (AA) patch in the beard region after taking oral paracetamol. The coexistence of these two distinct dermatological conditions at the same site suggests a potential shared pathogenic pathway, highlighting the isotopic phenomenon where a new dermatosis occurs at the site of a pre-existing lesion. The patient showed significant improvement with monthly intralesional triamcinolone acetonide injections. This case emphasizes the need for further studies to understand the immunological mechanisms linking AA and FDE, which could enhance clinical dermatology's understanding of such rare presentations.
