Serhan et al. demonstrated that HDM cysteine proteases directly activate TRPV1+ Tac1+ nociceptors, which form sensory clusters with MRGPRB2+ mast cells in the skin; the release of substance P from these neurons triggers rapid mast cell degranulation and drives early type 2 inflammation in atopic dermatitis models, identifying TRPV1 as a key initiator of cutaneous allergic responses [62]. Here, TAC1 is linked to atopic eczema.