Sarcocystis nesbitti related autoimmune diffuse alopecia

Background & Objective: Symptomatic sarcocystosis has been said to be rare until recent years, when there were reports of outbreaks of febrile myositis for travellers returning from the Malaysian island resorts. In 2012, an outbreak of Sarcocystis nesbitti infection involving 92 college students and staff occurred after returning from Pangkor Island, Malaysia. A few months after recovering from the febrile illness, some patients complained of hair loss. This study aimed to determine the prevalence, clinical features and outcome of this disorder. Methods: All patients who became sick in the outbreak were asked whether they had the hair loss. For those who had, they were interviewed with standard questionnaires, examined and investigated. Patients were followed-up via an online survey 2 years later. Results: Out of 89 patients who were ill, 19 patients (21.4%) complained of alopecia. The mean peak onset was 4 months after the initial illness. Eleven patients (57.9%) reported the hair fall of more than 100 per day. The other symptoms were itch 10 (52.6%), scaling 10 (52.6%), erythema 4 (21.1%), none had scarring. Eleven patients (57.8%) had positive antinuclear factor with high titre (speckled or nucleolar pattern). Two years after the event, 10 had complete or near complete spontaneous recovery, 1 had partial response and 1 had no improvement. Conclusions: A delayed transient diffuse alopecia is seen in close to half of patients with Sarcocystis nesbittiinfection. This high frequency of positive ANF suggested an immune-mediated mechanism.