Antibody-induced failure of botulinum toxin a therapy in cosmetic indications.

BACKGROUND Botulinum toxin (BT) is a safe and effective treatment for cosmetic indications. Formation of BT antibodies can occur but has previously been reported in cosmetic indications in two cases only. OBJECTIVE To report another four patients with this phenomenon. OBSERVATIONS Two patients received abobotulinumtoxinA; one received the current formulation of onabotulinumtoxinA and one both abobotulinumtoxinA and onabotulinumtoxinA. Complete secondary therapy failure (CSTF) occurred after 3-, 5-, 10-, and 13-injection series; cumulative treatment times of 18, 16, 25, and 65 months; and cumulative doses of 240 MU onabotulinumtoxinA, 245 MU abobotulinumtoxinA, 1,180 MU abobotulinumtoxinA, and 120 MU onabotulinumtoxinA/270 MU abobotulinumtoxinA, respectively. Average interinjection intervals were 87, 273, 150, and 119 days, and average single doses were 80 MU onabotulinumtoxinA, 68 MU abobotulinumtoxinA, 82 MU abobotulinumtoxinA, and 30 MU abobotulinumtoxinA/30 MU onabotulinumtoxinA. Risk factors for CSTF included booster injections (2 patients) and increased immune system reagibility (1 patient). BT antibody titers were 2.7, 7.0, and more than 10.0 mU/mL on the mouse diaphragm assay. CONCLUSIONS CSTF can occur after cosmetic BT injections in patients with high immune system reagibility and in patients receiving booster injections, but also in unremarkable patients with typical treatment parameters. Its incidence is unknown. Recommended treatment parameters may reduce the risk of CSTF, but may not eliminate it.