Neurogenic inflammation is known to induce lowering of interstitial fluid pressure (P_if) in mouse skin. This study examines the possible role of mast cell activation secondary to neuropeptide release in lowering of P_if by using Kit^W/Kit^W-v mice which are devoid of mast cells, including connective tissue mast cells (CTMCs). P_if was measured in paw skin of anesthetized (fentanyl/fluanison and midazolam; 1:1) mice with glass capillaries connected to a servo-controlled counterpressure system. In contrast to wild-type mice, intravenous administration of the mast cell activating Compound 48/80 induced no lowering of P_if in Kit^W/Kit^W-v mice. Intravenous challenge with Substance P (SP), calcitonin gene-related peptide (CGRP) or capsaicin induced a significant (P < 0.05) lowering of P_if in wild-type mice to -2.16 ± 0.28, -1.96 ± 0.11 and -2.22 ± 0.19 mmHg, respectively, compared with vehicle (-0.49 ± 0.11 mmHg). In Kit^W/Kit^W-v mice the P_if response to SP was completely abolished (-0.53 ± 0.32 mmHg) while the response to CGRP and capsaicin was attenuated (-1.33 ± 0.13 and -1.42 ± 0.13 mmHg, respectively) although significantly (P < 0.05) lowered compared to vehicle. Immunohistochemical analysis revealed no difference in distribution or density of SP- and CGRP-immunoreactive fibers in paws of Kit^W/Kit^W-v compared to wild-type mice. We conclude that lowering of P_if normally depends upon mast cells. However, the sensory nerves can also elicit a lowering of P_if which is mast cell independent.