Introduction Complex Regional Pain Syndrome (CRPS) is a chronic pain disorder characterised by significant autonomic features which typically develops in an extremity after acute tissue trauma. Symptoms may include continuing pain, sensory abnormalities like allodynia,hyperalgesia,hypoesthesia,vasomotor abnormalities in skin colour or temperature, sudomotor abnormalities of sweating or oedema and motor/trophic abnormalities in hair,skin,nails,tremor or muscle weakness.HPV vaccination is offered to all girls il Northern Ireland aged 14/15 years and recent plans have been made to offer it to boys starting late 2019. Since the introduction of HPV vaccination there have been case reports across the world describing various side effects after HPV vaccination, including Complex Regional Payn Syndrome. One report alone detailed 45 patients across 13 countries. In Japan the vaccination was temporarily halted as a consequence. The VaccineAdverseEventReportingSystem(VAERS) USA, has received 31.911 reports of adverse events following any HPV vaccination from which 22 (0.07%) reports met the criteria for complex regional pain syndrome (including reflex sympathetic dystrophy) as an adverse event. 21 cases were after Gardasil (HPV4) vaccine and 1 was after Cervarix (HPV2) vaccine.

Case We report a previously fit healthy 14 years old Irish girl. She had received her 2nd HPV (Gardasil) vaccine on 09/04/18 having received her 1st vaccine without any problems in October 2017. Twenty minutes post vaccine her left arm from the elbow down became swollen, purple and painful.Presentation was consistent, CRPS which was initially not diagnosed at first presentation to ED and Paediatrics. Correct diagnosis made four weeks post event and appropriate treatment initiated with full recovery withing eight months.

Laboratory investigations No significant abnormalities.

Conclusion There are documented cases of CRPS after HPV vaccine although is still controversial as to whether it is a vaccine or the effect of the trauma associated with inserting a needle which is the aetiological factor. This case highlights the need for better recognition of this condition amongst paediatricians as earlier initiation of treatment is associated with better long term outcome.