Telogen Effluvium: A Late Complication of Influenza A Sw H1N1 Pneumonia

In 2010, researchers at the National Institute of Respiratory Diseases in Mexico City, Mexico, reported a case series involving 7 patients who developed diffuse alopecia, identified as Telogen Effluvium, as a late complication following severe pneumonia caused by the Influenza A Sw H1N1 virus. This condition was observed after reviewing 102 charts from the first outbreak between April and June 2009. All patients experienced severe hair loss, with one female patient losing all scalp hair after discharge. However, none of the patients experienced body or pubic hair shedding. Remarkably, all patients' hair completely recovered after 4 months. The study highlighted that Telogen Effluvium, a common reversible hair loss condition, can be triggered by acute severe infections like the H1N1 influenza, which can cause an intense systemic inflammatory response. The severity of the initial illness was underscored by the fact that 5 of the 7 patients required mechanical ventilation due to acute lung injury. The majority of the cases were women, which suggests a need to consider the psychological impact of diffuse alopecia beyond the clinical resolution of the influenza.