Late-onset immune-mediated adverse effects after poly-L-lactic acid injection in non-HIV patients: clinical findings and long-term follow-up

BACKGROUND: It has been thought that poly-L-lactic acid (PLLA) injections do not have inflammatory side effects. Recent evidence shows that local/regional/systemic delayed adverse effects may appear with its use.

OBJECTIVE: To evaluate the clinical complaints, treatment response and long-term follow-up of non-HIV patients with delayed immune-mediated adverse effects related to PLLA injections.

METHODS: Prospective, case series study of 10 patients with delayed adverse effects related to PLLA injections. The inclusion criterion was defined as the onset at least 6 months after PLLA use, with 1 or more of the following clinical signs: oedema, skin induration, swelling/tender nodules with or without discharge of pus or filler material. Several systemic manifestations were also included. Patients with immediate side effects were excluded. Patients underwent clinical management and long-term follow-up.

RESULTS: The average latency period to the onset of symptoms was 19.2 months (range: 6-60). Tender, inflammatory nodules and facial oedema were commonly seen. One case presented a systemic granulomatous disorder as a complication. After 50.2 months of average follow-up (range: 38-78), 5 patients are in remission, 4 have recurrent bouts and the last case has been lost to follow-up.

CONCLUSION: Although infrequently, local and/or regional and/or systemic delayed and recurrent granulomatous reactions may complicate PLLA gel injections.