New onset systemic lupus erythematosus in a transgender man: possible role of feminizing sex hormones.

Systemic lupus erythematosus (SLE) is rare in men, and significantly more common in women. Sex hormone influences are believed to a play a role in these gender differences. We present the unusual case of a transgender man who had been taking feminizing sex hormones, who later developed new onset SLE with cardiorespiratory and renal involvement. While not definitive, this case raises intriguing possibilities on the relationship between the use of feminizing sex hormones and the development of SLE.