Multiple more effective than single purified protein derivative shot for warts

Multiple intralesional injections with purified protein derivative (PPD) leads to faster clearance of common warts compared with a single injection, although the latter is better tolerated, as shown in the results of an open‐label, superiority trial.

The trial randomized 66 patients (mean age, 31 years; 45.45 percent male) with at least three warts in two different anatomic sites to receive a single injection (n=29) and multiple injection (n=29) of PPD. All patients underwent treatment every 2 weeks for a maximum of six sessions.

Clearance rates were more favourable in the group that received multiple vs a single PPD injection (79.3 percent vs 58.6 percent; p=0.0236). Of note, the faster clearance associated with multiple injections was observed at each time point (p=0.048).

Clearance started to become evident at week 4, with the highest clearance rates recorded at week 12 for the single injection group and at week 10 for the multiple injection group. Patients who achieved clearance in both groups did not exhibit any recurrences 6 months after the last injection.

However, multiple injections were reported to be considerably more painful than a single injection (p=0.0005). Safety profiles were similar, with no significant between-group difference in the incidence of adverse events (p=0.1795).

The present data support the results of previous studies on single injections of PPD, although additional studies are warranted to develop a standard protocol for dose and interval of vaccinations, according to the researchers.