Pell and Pell-Lucas numbers as difference of two repdigits

Let $\{P_{n}\}_{n\geq 0}$ be the sequence of Pell numbers defined by $P_0=0$, $P_1 =1$ and $P_{n+2}= 2P_{n+1} +P_n$ for all $n\geq 0$ and let $\{Q_{n}\}_{n\geq 0}$ be its companion sequence, the Pell-Lucas numbers defined by $Q_0=Q_1 =2$ and $Q_{n+2}= 2Q_{n+1} +Q_n$ for all $n\geq 0$ . In this paper, we find all Pell and Pell-Lucas numbers which can be written as difference of two repdigits. It is shown that the largest Pell and Pell-Lucas numbers which can be written as difference of two repdigits are $$P_6=70= 77-7 \quad\quad \hbox{and} \quad\quad Q_7 = 478=555-77.$$