The agency points out that "both conditions can occur in non-vaccinated individuals and it is considered important to further review if the number of cases reported with HPV vaccine is greater than would be expected."
The review will consider any research that could help clarify the frequency of the two conditions after vaccination or identify any causal link, and on completion of the review, it will decide whether changes to product information are needed.
A recent report on these two syndromes, CRPS and POTS, occurring after HPV vaccination was published online May 20 and in the July issue of Clinical Rheumatology.
"The symptoms more often reported are chronic pain with paresthesias, headaches, fatigue, and orthostatic intolerance," writes Manuel Martínez-Lavín, MD, from the Rheumatology Department, Instituto Nacional de Cardiología Ignacio Chávez in Mexico City, Mexico. "Adverse reactions appear to be more frequent after HPV vaccination when compared to other type[s] of immunizations. Different isolated cases and small series have described the development of [CRPS], [POTS], and fibromyalgia after HPV vaccination."