Human Papillomavirus Vaccine Recombinant Bivalent: Two Cases of Telogen Effluvium in 11-Year-Old Girls

Two 11-year-old girls developed telogen effluvium, a form of temporary hair loss, after receiving the human papillomavirus (HPV) vaccine recombinant bivalent. The first girl experienced hair loss in July 2008, which worsened after her final vaccine dose, and her condition improved by April 2009. The second girl noticed hair loss one month after her first vaccine dose, which also worsened following subsequent doses; her condition began to resolve six months after her final dose. The authors suggest a probable relationship between the HPV vaccine and the onset of telogen effluvium, based on the timing of the events and the exclusion of other causes, aligning with the World Health Organization (WHO) criteria for causality assessment of adverse reactions to vaccines. No previous case reports of telogen effluvium associated with this vaccine were found in AdisBase, Medline, and Embase, but the WHO Adverse Drug Reaction (ADR) database contained seven reports of alopecia effluvium associated with the HPV vaccine.