This work deals with a three-component chemotaxis system \(\begin{aligned} \left\{ \begin{array}{llll} u_t=\Delta u-\nabla \cdot (u\chi _1(w)\nabla w)+w-\mu _1u^2,\quad & x\in \Omega ,\quad t>0,\\ v_t=\Delta v-\nabla \cdot (v\chi _2(w)\nabla w)+w+ruv-\mu _2v^2,\quad & x\in \Omega ,\quad t>0,\\ w_t=\Delta w+u+v-w,\quad & x\in \Omega ,\quad t>0,\\ \end{array} \right. \end{aligned}\) describing the spatiotemporal Alopecia Areata dynamics with signal-dependent sensitivity under homogeneous Neumann boundary conditions in a smoothly bounded domain \(\Omega \subset \mathbb {R}^n(n\ge 1)\) , where the parameters \(\mu _1\) , \(\mu _2\) , r are positive constants. The chemotactic function \(\chi _i(w)(i=1, 2)\) is smooth and satisfying some conditions. Given suitably regular initial data, it is shown that the corresponding initial-boundary value problem admits a unique global bounded classical solution. Furthermore, by constructing the appropriate energy function, it is proved that the unique coexistence equilibrium is globally convergent in a specific parameter regime. These results generalize and improve some well-known results in the literature.