背景
Discoloured leg syndrome (DLS) is a rare phenomenon that 能 发生 after receipt of an injected vaccine. It is a transient condition involv either an even or patchy colour change to the skin in the lower extremities (red, blue or purple) may or may not involve petechiae (pin-point red spots on the skin) 或者 swelling.
诊断
DLS 是 be diagnosed based on clinical presentation (e.g. symptom profile, onset of symptoms and symptom resolution).
Unlike injection site reactions (ISRs), DLS does not radiate from the site of injection, and can impact 一 or both leg秒, even if only one injection has been administered. Discolouration can also extend up to the pelvis.
Investigations are generally not required. Despite the presence of petechiae, there is no drop in platelet count.
As DLS involves skin changes and symptoms can occur quickly, it is important to differentiate it from anaphylaxis, especially if symptoms start within 30 minutes of vaccination.
Association and incidence
DLS is reported at a rate of 58 per 100,000 children vaccinated. Although the median onset time for colour change is approximately 3.5 hours, DLS can be seen quite quickly post-vaccination (within 30 minutes). Where symptoms of petechiae occur, the median onset time is 12 hours following vaccination. Generally, colour change (median duration = approximately 2 hours) does not last as long as petechiae (median duration = 54 hours).
治疗
As a precaution, assessment of airway, breathing and circulation is advised.
Symptoms of DLS are transient and will resolve on their own without treatment.
Any adverse event following immunisation (AEFI), including DLS, should be reported to the adverse event reporting service in your jurisdiction. In Victoria, this is 赛维克.
对未来剂量的影响
Recurrence of DLS 是 uncommon, but can occur. However, DLS 是 not a contraindication to receiving future vaccines. Given that DLS appears to be age-related, families can be reassured that children are less likely to experience symptoms as they get older.
资源
作者： Rachael McGuire (MVEC Education Nurse Coordinator), Dr Shidan Tosif (Senior Research Fellow, SAEFVIC) and Prof Nigel Crawford (Director, MVEC).
日期： April 2026
本章节内的材料将随着新信息和新疫苗的出现而进行更新。墨尔本疫苗教育中心（MVEC）职员定期审阅材料的准确性。
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